JavaScript String Methods
Tags: javascript, webdev, beginners
Published: 2023-07-14 21:20:31

## <u>INTRODUCTION</u>

A straightforward and effective programming language called JavaScript is used to build technologies and software for several applications. Its use has expanded since its introduction, from web development to software for NASA and programming interfaces. There are several topics to master and numerous applications for the language because it is so versatile.

This article will discuss string methods in JavaScript that alter and work with string values. We'll go over built-in string methods and others that can work with strings to accomplish a variety of tasks. You will also see a few samples of syntax in CodePen that you may utilize to further your comprehension.

Let's get started now without further ado.


### <u>Explaining JavaScript Strings</u>

The JavaScript string is a data type that differs from numerical data types like int in that it is used to express information as text. In particular, a string can include any character while an int value can only be an integer. They are therefore frequently employed in the creation of software across various domains and linguistic systems.

Due to the prevalence and demand for string data, JavaScript provides a wide range of options for dealing with and altering strings. In reality, there are more than 30 different ways to change and work with string values.

## <u>String methods in JavaScript are what?</u>

Strings have a plethora of uses, therefore it's critical to comprehend how to take benefit of them. Possibly the most frequent action you will take is to change a string in some way. JavaScript has a string object that enables the execution of methods and properties on string values to help with that process.

Strings can be used, among other things, to prevent malicious code from being injected into software or programs. Regex, often known as a regular expression, is used in this process even though it has nothing in common with regular expressions. Regular expressions are patterns used to strings to make sure they adhere to predetermined formatting standards. 

## <u>JavaScript "Built-in String Methods" </u>

Strings are objects in many languages, which means they contain a variety of properties and methods to enhance their functionality. But because strings are a primitive data type in JavaScript, they lack any built-in functions or attributes. Despite this, JavaScript does support a number of methods and a few string properties. Strings can still be expanded in JavaScript since they are treated as objects when methods or properties are used. Despite not being designed for producing string objects, the JavaScript library or framework's string object is responsible for this capability. Use string objects with caution as they slow down processing and could produce incorrect results. 

## <u>Learn how to use JavaScript's string methods.</u>

It's true that employing string techniques is comparatively simple. Understanding what is happening, however, is a separate subject. Let's use an illustration to further explain. After all, employing a string method only requires comprehension of the syntax. Let's examine a code example of the syntax below keeping it in mind. 

```
"let str = “John Doe”;str.text();" 
```

Every string method starts with that. An initial variable contains a simple string value. Using the dot notation, you can then connect the required method to the string variable before concluding with parenthesis and a semicolon. The trim() techniques are demonstrated in the following snippet of code.

```
"let str = “Yes, but John Doe?”;str.trim();
/*Would return the string “Yes,butJohnDoe?”*/" 
```

"Easy enough, yes? What happens if that method calls for a parameter? The method will then accept certain requirements for how to handle the string value. Things are slightly altered by this conduct. Let's take a look at a straightforward method with parameters example. The code that follows removes any whitespace from a string in the same manner as the code that precedes it. This time, though, the replace() method is utilized. The first parameter of the replace method is the string to search for, and the second specifies the value to replace with the target. 


```
"let str = “I love doughnuts.”;
str.replace(/\s/g,'');\
/*Would return the string “Ilovedoughnuts.”*/" 
```

The code above instructs JavaScript to eliminate all instances of any white space by using a regular expression that is equivalent to "all-white space, inclusive". Let's look at a complete list of the string methods that are available in JavaScript now that we have studied what string methods are and how to utilize them. 

## <u>METHODS</u>

✔️ JavaScript String length
Returns the number of characters in a string

✔️ JavaScript String replace()
replace a substring/pattern in the string

✔️ JavaScript String indexOf()
Returns the first index of occurrence of a value

✔️ JavaScript String lastIndexOf()
Returns the last index of occurrence of a value

✔️ Javascript String startsWith()
Checks if a string begins with a specified string

✔️ Javascript String endsWith()
Checks if a string ends with a specified string

✔️ Javascript String toUpperCase()
Returns uppercase of a string

✔️ Javascript String toLowerCase()
Returns lowercase representation of a string

✔️ Javascript String includes()
Checks if given string is found inside a string

✔️ JavaScript String repeat()
Returns a string by repeating it given times

✔️ JavaScript String charAt()
Returns character at a specified index in string

✔️ JavaScript String charCodeAt()
Returns Unicode of the character at given index

✔️ JavaScript String fromCharCode()
Returns a string from the given UTF-16 code units

✔️ Javascript String substring()
Returns a specified part of the string

✔️ Javascript String padStart()
Pads a string at the start to a given length

✔️ Javascript String padEnd()
Pads a string at the end to a given length

✔️ JavaScript String codePointAt()
Returns the Unicode point value at given index

✔️ JavaScript String fromCodePoint()
Returns a string using the given code points

✔️ Javascript String match()
Returns result of matching string with a regex

✔️ Javascript String matchAll()
Returns iterator of results matching with a regex

✔️ Javascript String localeCompare()
Compares two strings in the current locale

✔️ Javascript String search()
Searches for specified value in the string

✔️ JavaScript String replaceAll()
Returns string by replacing all matching patterns

✔️ JavaScript String concat()
Concatenates the arguments to the calling string

✔️ JavaScript String split()
Returns the string divided into list of substring

✔️ JavaScript String trim()
Removes whitespace from both ends of a string

✔️ JavaScript String slice()
Extracts and returns a section of the string