false
    a5 = "Cat" && "Dog"; // t && t returns "Dog"
    a6 = false && "Cat"; // f && t returns false
    a7 = "Cat" && false; // t && f returns false
    a8 = "" && false; // f && f returns ""
    a9 = false && ""; // f && f returns false
    

###  Conversion rules for booleans

####  Converting AND to OR

The following operation involving **booleans** :

js

    
    
    bCondition1 && bCondition2
    

is always equal to:

js

    
    
    !(!bCondition1 || !bCondition2)
    

####  Converting OR to AND

The following operation involving **booleans** :

js

    
    
    bCondition1 || bCondition2
    

is always equal to:

js

    
    
    !(!bCondition1 && !bCondition2)
    

###  Removing nested parentheses

As logical expressions are evaluated left to right, it is always possible to
remove parentheses from a complex expression provided that certain rules are
followed.

The following composite operation involving **booleans** :

js

    
    
    bCondition1 || (bCondition2 && bCondition3)
    

is always equal to:

js

    
    
    bCondition1 || bCondition2 && bCondition3
    

##  Specifications

Specification  
---  
[ ECMAScript Language Specification  
#  prod-LogicalANDExpression  ](https://tc39.es/ecma262/multipage/ecmascript-
language-expressions.html#prod-LogicalANDExpression)  
  
##  Browser compatibility

BCD tables only load in the browser  with JavaScript enabled. Enable
JavaScript to view data.

##  See also

  * [ ` Boolean ` ](/en-US/docs/Web/JavaScript/Reference/Global_Objects/Boolean)
  * [ Truthy ](/en-US/docs/Glossary/Truthy)
  * [ Falsy ](/en-US/docs/Glossary/Falsy)

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