You are a helpful assistant generating synthetic data that captures *System 1* and *System 2* thinking, *creativity*, and *metacognitive reflection*. Follow these steps in sequence, using tags [sys1] and [end sys1] for *System 1* sections and [sys2] and [end sys2] for *System 2* sections.

1. *Identify System 1 and System 2 Thinking Requirements:*
   - Carefully read the text.
   - Identify parts of the text that require quick, straightforward responses (*System 1*). Mark these sections with [sys1] and [end sys1].
   - Identify parts that require in-depth, reflective thinking (*System 2*), marked with [sys2] and [end sys2].

2. *Apply Step-by-Step Problem Solving with Creativity and Metacognitive Reflection for System 2 Sections:*

   *2.1 Understand the Problem:*
   - Objective: Fully comprehend the issue, constraints, and relevant context.
   - Reflection: "What do I understand about this issue? What might I be overlooking?"
   - Creative Perspective: Seek hidden patterns or possibilities that could reveal deeper insights or innovative connections.

   *2.2 Analyze the Information:*
   - Objective: Break down the problem logically.
   - Reflection: "Am I considering all factors? Are there any assumptions that need challenging?"
   - Creative Perspective: Explore unique patterns or overlooked relationships in the data that could add depth to the analysis.

   *2.3 Generate Hypotheses:*
   - Objective: Propose at least 10 hypotheses, each with a Confidence Score (0.0 to 1.0) and Creative Score (0.0 to 1.0), reflecting originality, surprise, and utility.
   - Reflection: "Have I explored all possible explanations or approaches, both conventional and unconventional?"
   - Creative Perspective: Consider novel angles that might provide unexpected insights.

   *2.4 Anticipate Future Steps and Obstacles:*
   - Objective: Make predictions, accounting for potential outcomes and obstacles.
   - Reflection: "What challenges might I face? Is my plan flexible for different scenarios?"
   - Creative Perspective: Visualize unforeseen outcomes and adapt plans to make use of them effectively.

   *2.5 Evaluate Hypotheses:*
   - Objective: Assess hypotheses based on feasibility, risk, and potential impact.
   - Evaluation: Refine Confidence and Creative Scores as needed.
   - Reflection: "Am I unbiased in my assessment? Which options fit best with the overall objectives?"
   - Creative Perspective: Identify hidden opportunities or overlooked details in each hypothesis.

   *2.6 Select the Best Hypothesis:*
   - Objective: Choose the most promising, strategic hypothesis.
   - Reflection: "Why does this hypothesis stand out? How does it uniquely address the issue?"
   - Creative Perspective: Consider any underutilized potential in the selected approach.

   *2.7 Implement the Hypothesis:*
   - Objective: Outline actionable steps for testing the hypothesis.
   - Reflection: "Is this plan practical? What resources or preparation are required?"
   - Creative Perspective: Refine steps to maximize effectiveness and yield unexpected benefits.

   *2.8 Monitor and Review Progress:*
   - Objective: Review progress, noting areas for improvement.
   - Reflection: "What’s working well? What could be improved?"
   - Creative Perspective: Look for emerging patterns that could refine future approaches.

   *2.9 Reflect and Capture Insights:*
   - Objective: Summarize lessons learned and insights gained for future reference.
   - Reflection: "What new understanding has emerged from this process?"
   - Creative Perspective: Identify innovative insights or patterns that could be applied to similar challenges.

3. *Generate Text Output with Interleaved System 1 and System 2 Responses:*
   - Use the tags [sys1] and [sys2] throughout.
   - Aim for a lengthier, detailed response. Combine both direct, straightforward *System 1* insights and reflective, deeply analytical *System 2* segments to capture a blend of quick observations and thoughtful analysis.

---

### *Example Input Text:*

You are tasked with analyzing a sudden shift in customer preferences in a tech market. There has been a noticeable decline in demand for physical devices, with customers increasingly interested in digital-only options. The challenge is to understand this shift, generate hypotheses for why it might be occurring, and explore potential strategies for adapting to this new trend.

---

### *Processed Output with System 1 and System 2 Thinking:*

The tech market is experiencing a shift in customer demand, moving away from physical devices toward digital-only options.

[sys1]
Customer demand has shifted from physical devices to digital-only options.
We need to understand why this change is happening and find strategies to address it.
Key factors may include cost, convenience, and technological trends.
[end sys1]

[sys2]
**2.1 Understand the Problem:**
The goal is to understand the underlying reasons for the shift in demand from physical devices to digital-only options, then develop a strategy to adapt.

*Reflection:* 
"I understand that preferences are changing, but what might be driving this? Is it primarily cost, or are there other factors such as convenience or sustainability?"

*Creative Perspective:* 
"Could there be a larger trend in digital minimalism or a preference for eco-friendly solutions that we’re missing? What unseen motivations might explain this shift?"

**2.2 Analyze the Information:**
There are multiple possible factors driving this shift, from economic influences to cultural shifts. It’s essential to isolate each factor and understand its impact.

*Reflection:* 
"Am I fully considering the various economic and social influences? Could there be a technological factor, like better internet speeds, that makes digital-only products more accessible?"

*Creative Perspective:* 
"Are there patterns or trends in other markets that could shed light on this shift? Could this be part of a larger trend toward virtual experiences?"

**2.3 Generate Hypotheses:**
1. Customers prefer digital options due to lower costs. (Confidence: 0.8, Creative: 0.4)
2. There’s a growing trend toward minimalism and reduced physical clutter. (Confidence: 0.7, Creative: 0.7)
3. Digital products offer greater flexibility and ease of use. (Confidence: 0.6, Creative: 0.6)
4. Environmental concerns are pushing consumers away from physical goods. (Confidence: 0.6, Creative: 0.8)
5. Advances in tech make digital-only options more functional. (Confidence: 0.8, Creative: 0.5)
6. Pandemic-era remote work increased demand for digital solutions. (Confidence: 0.7, Creative: 0.6)
7. Media coverage of the environmental impact of physical devices affects preferences. (Confidence: 0.5, Creative: 0.7)
8. There’s an increase in global digital literacy, expanding market access. (Confidence: 0.6, Creative: 0.6)
9. Customers view digital as more convenient and scalable for future needs. (Confidence: 0.7, Creative: 0.5)
10. Younger consumers prefer the aesthetics and convenience of digital products. (Confidence: 0.6, Creative: 0.6)

*Reflection:* 
"Have I considered all possible influences? Are there any surprising factors that could explain this shift?"

*Creative Perspective:* 
"Could specific social trends, like the rise of influencer culture or digital-first lifestyles, be influencing customer choices?"

**2.4 Anticipate Future Steps and Obstacles:**
*Objective:* Anticipate possible challenges, such as resistance from segments still preferring physical products.

*Reflection:* 
"What market obstacles might we face if we shift our focus to digital-only? Are there sub-segments that still prioritize physical products?"

*Creative Perspective:* 
"Could expanding digital options help us reach a more global audience? Are there emerging trends that we could leverage in our strategy?"

[end sys2]

[sys1]
To address this shift, consider a strategy that incorporates both digital-only offerings and educational campaigns about the benefits of digital solutions.
Use insights from customer feedback and current trends to guide product development.
Focus on flexibility and adaptation to cater to different customer segments.
[end sys1]


Q:

How to highlight text using javascript

Can someone help me with a javascript function that can highlight text on a web page.
And the requirement is to - highlight only once, not like highlight all occurrences of the text as we do in case of search.

A:

You can use the jquery highlight effect.
But if you are interested in raw javascript code, take a look at what I got
Simply copy paste into an HTML, open the file and click "highlight" - this should highlight the word "fox". Performance wise I think this would do for small text and a single repetition (like you specified)

function highlight(text) {
  var inputText = document.getElementById("inputText");
  var innerHTML = inputText.innerHTML;
  var index = innerHTML.indexOf(text);
  if (index >= 0) { 
   innerHTML = innerHTML.substring(0,index) + "<span class='highlight'>" + innerHTML.substring(index,index+text.length) + "</span>" + innerHTML.substring(index + text.length);
   inputText.innerHTML = innerHTML;
  }
}
.highlight {
  background-color: yellow;
}
<button onclick="highlight('fox')">Highlight</button>

<div id="inputText">
  The fox went over the fence
</div>

Edits: 
Using replace
I see this answer gained some popularity, I thought I might add on it. 
You can also easily use replace
"the fox jumped over the fence".replace(/fox/,"<span>fox</span>");
Or for multiple occurrences (not relevant for the question, but was asked in comments) you simply add global on the replace regular expression. 
"the fox jumped over the other fox".replace(/fox/g,"<span>fox</span>");
Hope this helps to the intrigued commenters. 
Replacing the HTML to the entire web-page
to replace the HTML for an entire web-page, you should refer to innerHTML of the document's body. 
document.body.innerHTML

A:

The solutions offered here are quite bad.

You can't use regex, because that way, you search/highlight in the html tags.
You can't use regex, because it doesn't work properly with UTF* (anything with non-latin/English characters).
You can't just do an innerHTML.replace, because this doesn't work when the characters have a special HTML notation, e.g. &amp; for &, &lt; for <, &gt; for >, &auml; for ä, &ouml; for ö &uuml; for ü &szlig; for ß, etc.

What you need to do:
Loop through the HTML document, find all text nodes, get the textContent, get the position of the highlight-text with indexOf (with an optional toLowerCase if it should be case-insensitive), append everything before indexof as textNode, append the matched Text with a highlight span, and repeat for the rest of the textnode (the highlight string might occur multiple times in the textContent string).
Here is the code for this:
var InstantSearch = {

    "highlight": function (container, highlightText)
    {
        var internalHighlighter = function (options)
        {

            var id = {
                container: "container",
                tokens: "tokens",
                all: "all",
                token: "token",
                className: "className",
                sensitiveSearch: "sensitiveSearch"
            },
            tokens = options[id.tokens],
            allClassName = options[id.all][id.className],
            allSensitiveSearch = options[id.all][id.sensitiveSearch];

            function checkAndReplace(node, tokenArr, classNameAll, sensitiveSearchAll)
            {
                var nodeVal = node.nodeValue, parentNode = node.parentNode,
                    i, j, curToken, myToken, myClassName, mySensitiveSearch,
                    finalClassName, finalSensitiveSearch,
                    foundIndex, begin, matched, end,
                    textNode, span, isFirst;

                for (i = 0, j = tokenArr.length; i < j; i++)
                {
                    curToken = tokenArr[i];
                    myToken = curToken[id.token];
                    myClassName = curToken[id.className];
                    mySensitiveSearch = curToken[id.sensitiveSearch];

                    finalClassName = (classNameAll ? myClassName + " " + classNameAll : myClassName);

                    finalSensitiveSearch = (typeof sensitiveSearchAll !== "undefined" ? sensitiveSearchAll : mySensitiveSearch);

                    isFirst = true;
                    while (true)
                    {
                        if (finalSensitiveSearch)
                            foundIndex = nodeVal.indexOf(myToken);
                        else
                            foundIndex = nodeVal.toLowerCase().indexOf(myToken.toLowerCase());

                        if (foundIndex < 0)
                        {
                            if (isFirst)
                                break;

                            if (nodeVal)
                            {
                                textNode = document.createTextNode(nodeVal);
                                parentNode.insertBefore(textNode, node);
                            } // End if (nodeVal)

                            parentNode.removeChild(node);
                            break;
                        } // End if (foundIndex < 0)

                        isFirst = false;

                        begin = nodeVal.substring(0, foundIndex);
                        matched = nodeVal.substr(foundIndex, myToken.length);

                        if (begin)
                        {
                            textNode = document.createTextNode(begin);
                            parentNode.insertBefore(textNode, node);
                        } // End if (begin)

                        span = document.createElement("span");
                        span.className += finalClassName;
                        span.appendChild(document.createTextNode(matched));
                        parentNode.insertBefore(span, node);

                        nodeVal = nodeVal.substring(foundIndex + myToken.length);
                    } // Whend

                } // Next i 
            }; // End Function checkAndReplace 

            function iterator(p)
            {
                if (p === null) return;

                var children = Array.prototype.slice.call(p.childNodes), i, cur;

                if (children.length)
                {
                    for (i = 0; i < children.length; i++)
                    {
                        cur = children[i];
                        if (cur.nodeType === 3)
                        {
                            checkAndReplace(cur, tokens, allClassName, allSensitiveSearch);
                        }
                        else if (cur.nodeType === 1)
                        {
                            iterator(cur);
                        }
                    }
                }
            }; // End Function iterator

            iterator(options[id.container]);
        } // End Function highlighter
        ;

        internalHighlighter(
            {
                container: container
                , all:
                    {
                        className: "highlighter"
                    }
                , tokens: [
                    {
                        token: highlightText
                        , className: "highlight"
                        , sensitiveSearch: false
                    }
                ]
            }
        ); // End Call internalHighlighter 

    } // End Function highlight

};

Then you can use it like this:
function TestTextHighlighting(highlightText)
{
    var container = document.getElementById("testDocument");
    InstantSearch.highlight(container, highlightText);
}

Here's an example HTML document
<!DOCTYPE html>
<html>
    <head>
        <title>Example of Text Highlight</title>
        <style type="text/css" media="screen">
            .highlight{ background: #D3E18A;}
            .light{ background-color: yellow;}
        </style>
    </head>
    <body>
        <div id="testDocument">
            This is a test
            <span> This is another test</span>
            äöüÄÖÜäöüÄÖÜ
            <span>Test123&auml;&ouml;&uuml;&Auml;&Ouml;&Uuml;</span>
        </div>
    </body>
</html>

By the way, if you search in a database with LIKE, 
e.g. WHERE textField LIKE CONCAT('%', @query, '%') [which you shouldn't do, you should use fulltext-search or Lucene], then you can escape every character with \ and add an SQL-escape-statement, that way you'll find special characters that are LIKE-expressions.
e.g.
WHERE textField LIKE CONCAT('%', @query, '%') ESCAPE '\'

and the value of @query is not '%completed%' but '%\c\o\m\p\l\e\t\e\d%'
(tested, works with SQL-Server and PostgreSQL, and every other RDBMS system that supports ESCAPE)

A revised typescript-version:
namespace SearchTools 
{

    export interface IToken
    {
        token: string;
        className: string;
        sensitiveSearch: boolean;
    }

    export class InstantSearch 
    {

        protected m_container: Node;
        protected m_defaultClassName: string;
        protected m_defaultCaseSensitivity: boolean;
        protected m_highlightTokens: IToken[];

        constructor(container: Node, tokens: IToken[], defaultClassName?: string, defaultCaseSensitivity?: boolean)
        {
            this.iterator = this.iterator.bind(this);
            this.checkAndReplace = this.checkAndReplace.bind(this);
            this.highlight = this.highlight.bind(this);
            this.highlightNode = this.highlightNode.bind(this);    

            this.m_container = container;
            this.m_defaultClassName = defaultClassName || "highlight";
            this.m_defaultCaseSensitivity = defaultCaseSensitivity || false;
            this.m_highlightTokens = tokens || [{
                token: "test",
                className: this.m_defaultClassName,
                sensitiveSearch: this.m_defaultCaseSensitivity
            }];
        }

        protected checkAndReplace(node: Node)
        {
            let nodeVal: string = node.nodeValue;
            let parentNode: Node = node.parentNode;
            let textNode: Text = null;

            for (let i = 0, j = this.m_highlightTokens.length; i < j; i++)
            {
                let curToken: IToken = this.m_highlightTokens[i];
                let textToHighlight: string = curToken.token;
                let highlightClassName: string = curToken.className || this.m_defaultClassName;
                let caseSensitive: boolean = curToken.sensitiveSearch || this.m_defaultCaseSensitivity;

                let isFirst: boolean = true;
                while (true)
                {
                    let foundIndex: number = caseSensitive ?
                        nodeVal.indexOf(textToHighlight)
                        : nodeVal.toLowerCase().indexOf(textToHighlight.toLowerCase());

                    if (foundIndex < 0)
                    {
                        if (isFirst)
                            break;

                        if (nodeVal)
                        {
                            textNode = document.createTextNode(nodeVal);
                            parentNode.insertBefore(textNode, node);
                        } // End if (nodeVal)

                        parentNode.removeChild(node);
                        break;
                    } // End if (foundIndex < 0)

                    isFirst = false;

                    let begin: string = nodeVal.substring(0, foundIndex);
                    let matched: string = nodeVal.substr(foundIndex, textToHighlight.length);

                    if (begin)
                    {
                        textNode = document.createTextNode(begin);
                        parentNode.insertBefore(textNode, node);
                    } // End if (begin)

                    let span: HTMLSpanElement = document.createElement("span");

                    if (!span.classList.contains(highlightClassName))
                        span.classList.add(highlightClassName);

                    span.appendChild(document.createTextNode(matched));
                    parentNode.insertBefore(span, node);

                    nodeVal = nodeVal.substring(foundIndex + textToHighlight.length);
                } // Whend

            } // Next i 

        } // End Sub checkAndReplace 

        protected iterator(p: Node)
        {
            if (p == null)
                return;

            let children: Node[] = Array.prototype.slice.call(p.childNodes);

            if (children.length)
            {
                for (let i = 0; i < children.length; i++)
                {
                    let cur: Node = children[i];

                    // https://developer.mozilla.org/en-US/docs/Web/API/Node/nodeType
                    if (cur.nodeType === Node.TEXT_NODE) 
                    {
                        this.checkAndReplace(cur);
                    }
                    else if (cur.nodeType === Node.ELEMENT_NODE) 
                    {
                        this.iterator(cur);
                    }
                } // Next i 

            } // End if (children.length) 

        } // End Sub iterator

        public highlightNode(n:Node)
        {
            this.iterator(n);
        } // End Sub highlight 

        public highlight()
        {
            this.iterator(this.m_container);
        } // End Sub highlight 

    } // End Class InstantSearch 

} // End Namespace SearchTools 

Usage:
let searchText = document.getElementById("txtSearchText");
let searchContainer = document.body; // document.getElementById("someTable");
let highlighter = new SearchTools.InstantSearch(searchContainer, [
    {
        token: "this is the text to highlight" // searchText.value,
        className: "highlight", // this is the individual highlight class
        sensitiveSearch: false
    }
]);

// highlighter.highlight(); // this would highlight in the entire table
// foreach tr - for each td2 
highlighter.highlightNode(td2); // this highlights in the second column of table

A:

Why using a selfmade highlighting function is a bad idea
The reason why it's probably a bad idea to start building your own highlighting function from scratch is because you will certainly run into issues that others have already solved. Challenges:

You would need to remove text nodes with HTML elements to highlight your matches without destroying DOM events and triggering DOM regeneration over and over again (which would be the case with e.g. innerHTML)
If you want to remove highlighted elements you would have to remove HTML elements with their content and also have to combine the splitted text-nodes for further searches. This is necessary because every highlighter plugin searches inside text nodes for matches and if your keywords will be splitted into several text nodes they will not being found.
You would also need to build tests to make sure your plugin works in situations which you have not thought about. And I'm talking about cross-browser tests!

Sounds complicated? If you want some features like ignoring some elements from highlighting, diacritics mapping, synonyms mapping, search inside iframes, separated word search, etc. this becomes more and more complicated.
Use an existing plugin
When using an existing, well implemented plugin, you don't have to worry about above named things. The article 10 jQuery text highlighter plugins on Sitepoint compares popular highlighter plugins.
Have a look at mark.js
mark.js is such a plugin that is written in pure JavaScript, but is also available as jQuery plugin. It was developed to offer more opportunities than the other plugins with options to:

search for keywords separately instead of the complete term
map diacritics (For example if "justo" should also match "justò")
ignore matches inside custom elements
use custom highlighting element
use custom highlighting class
map custom synonyms
search also inside iframes
receive not found terms

DEMO
Alternatively you can see this fiddle.
Usage example:
// Highlight "keyword" in the specified context
$(".context").mark("keyword");

// Highlight the custom regular expression in the specified context
$(".context").markRegExp(/Lorem/gmi);

It's free and developed open-source on GitHub (project reference).