JavaScript Comparison operators

Last Updated : 10 Sep, 2020

Below is the example of the comparison operators.

Example 1:

<script> 
    function gfg() { 
    let val1 = 5; 
    // Equality Operators
    document.write(val1 == 5);
    document.write("<br>");
    // Relational Operators
    document.write(val1 > 0);
    } 
    gfg(); 
</script> 

Output:
```
true
true
```

Operators are used to perform specific mathematical and logical computations on operands. Like C, C++, Java, Python and various other languages, JavaScript also supports Comparison operations. Comparison operators are used in logical statements to determine equality or difference between variables or values. There are various comparison operators supported by JavaScript:

Equality Operators
Relational Operators

Equality Operators

Equality (==): This operator is used to compare the equality of two operands. If equal then the condition is true otherwise false.

Syntax:

x == y

Below examples illustrate the (==) operator in JavaScript:

Example 1:

<script>
    // Illustration of (==) operator
    let val1 = 5;
    let val2 = '5';
  
    // Checking of operands
    console.log(val1 == 5);
    console.log(val2 == 5);        
    console.log(val1 == val1);
  
    // Check against null and boolean value
    console.log(0 == false);   
    console.log(0 == null);
</script>

Output:

> true
> true
> true
> true
> false

Example 2:

<script>
    // Illustration of (==) operator
    let obj1 = {'val1': 'value'};
    let obj2 = {'val2': 'value'};
  
    // Checking of operands
    console.log(obj1.val1 == 'value');        
    console.log(obj1 == obj2);
    console.log(obj1.val1 == obj2.val2);
  
    // Check against undefined
    console.log(0 == undefined);   
    console.log(null == undefined);
</script>

Output:

> true
> false
> true
> false
> true

Inequality (!=): This operator is used to compare the inequality of two operands. If equal then the condition is false otherwise true.

Syntax:

x != y

Below examples illustrate the (!=) operator in JavaScript:

Example 1:

<script>
    // Illustration of (!=) operator
    let val1 = 5;
    let val2 = '5';
  
    // Checking of operands
    console.log(val1 != 6);
    console.log(val2 != '5');        
    console.log(val1 != val1);
  
    // Check against null and boolean value
    console.log(0 != false);   
    console.log(0 != null);
</script>

Output:

> true
> false
> false
> false
> true

Example 2:

<script>
    // Illustration of (!=) operator
    let obj1 = {'val1': 'value'};
    let obj2 = {'val2': 'value'};
  
    // Checking of operands
    console.log(obj1.val1 != 'value');        
    console.log(obj1 != obj2);
    console.log(obj1.val1 != obj2.val2);
  
    // Check against undefined
    console.log(0 != undefined);   
    console.log(null != undefined);
</script>

Output:

> false
> true
> false
> true
> false

Strict equality (===): This operator is used to compare the equality of two operands with type. If both value and type are equal then the condition is true otherwise false.

Syntax:

x === y

Below examples illustrate the (===) operator in JavaScript:

Example 1:

<script>
    // Illustration of (===) operator
    let val1 = 5;
    let val2 = '5';
  
    // Checking of operands
    console.log(val1 === 6);
    console.log(val2 === '5');        
    console.log(val1 === val1);
  
    // Check against null and boolean value
    console.log(0 === false);   
    console.log(0 === null);
</script>

Output:

> false
> true
> true
> false
> false

Example 2:

<script>
    // Illustration of (===) operator
    let obj1 = {'val1': 'value'};
    let obj2 = {'val2': 'value'};
  
    // Checking of operands
    console.log(obj1.val1 === 'value');        
    console.log(obj1 === obj2);
    console.log(obj1.val1 === obj2.val2);
  
    // Check against undefined
    console.log(0 === undefined);   
    console.log(null === undefined);
</script>

Output:

> true
> false
> true
> false
> false

Strict inequality (!==): This operator is used to compare the inequality of two operands with type. If both value and type are not equal then the condition is true otherwise false.

Syntax:

x !== y

Below examples illustrate the (!==) operator in JavaScript:

Example 1:

<script>
 // Illustration of (!==) operator
 let val1 = 5;
 let val2 = '5';
  
 // Checking of operands
 console.log(val1 !== 6);
 console.log(val2 !== '5');        
 console.log(val1 !== val1);
  
 // Check against null and boolean value
 console.log(0 !== false);   
 console.log(0 !== null);
</script>

Output:

> true
> false
> false
> true
> true

Example 2:

<script>
    // Illustration of (!==) operator
    let obj1 = {'val1': 'value'};
    let obj2 = {'val2': 'value'};
  
    // Checking of operands
    console.log(obj1.val1 !== 'value');        
    console.log(obj1 !== obj2);
    console.log(obj1.val1 !== obj2.val2);
  
    // Check against undefined
    console.log(0 !== undefined);   
    console.log(null !== undefined);
</script>

Output:

> false
> true
> false
> true
> true

Relational Operators

Greater than operator (>): This operator is used to checks whether the left side value is greater than the right side value. If value is greater then the condition is true otherwise false.

Syntax:

x > y

Below examples illustrate the (>) operator in JavaScript:

Example 1:

<script>
    // Illustration of (>) operator
    let val1 = 5;
    let val2 = "5";
  
    // Checking of operands
    console.log(val1 > 0);
    console.log(val2 > "10");        
    console.log(val1 > "10");
    console.log(val2 > 0);
</script>

Output:

> true
> true
> false
> true

Example 2:

<script>    
    // Illustration of (>) operator
    let obj1 = {'val1': 1};
    let obj2 = {'val2': 3};
  
    // Checking of operands
    console.log(obj1.val1 > 0);        
    console.log(obj1 > obj2);
    console.log(obj1.val1 > obj2.val2);
    console.log(obj2 > obj1);
    console.log(obj2.val2 > obj1.val1);
</script>

Output:

> true
> false
> false
> false
> true

Greater than or equal operator (>=): This operator is used to checks whether the left side operand is greater than or equal to the right side operand. If value is greater than or equal then the condition is true otherwise false.

Syntax:

x >= y

Below examples illustrate the (>=) operator in JavaScript:

Example 1:

<script>
 // Illustration of (>=) operator
 let val1 = 5;
 let val2 = "5";
  
 // Checking of operands
 console.log(val1 >= 5);
 console.log(val2 >= "15");        
 console.log(val1 >= "5");
 console.log(val2 >= 15);
</script>

Output:

> true
> true
> true
> false

Example 2:

<script>
    // Illustration of (>=) operator
    let obj1 = {'val1': 1};
    let obj2 = {'val2': 3};
  
    // Checking of operands
    console.log(obj1.val1 >= 0);        
    console.log(obj1 >= obj2);
    console.log(obj1.val1 >= obj2.val2);
    console.log(obj2 >= obj1);
    console.log(obj2.val2 >= obj1.val1);
</script>

Output:

> true
> true
> false
> true
> true

Less than operator (<): This operator is used to checks whether the left side value is less than right side value. If yes then the condition is true otherwise false.

Syntax:

x < y

Below examples illustrate the (<) operator in JavaScript:

Example 1:

<script>
 // Illustration of (<) operator
 let val1 = 5;
 let val2 = "5";
  
 // Checking of operands
 console.log(val1 < 15);
 console.log(val2 < "0");        
 console.log(val1 < "0");
 console.log(val2 < 15);
</script>

Output:

> true
> false
> false
> true

Example 2:

<script>
    // Illustration of (<) operator
    let obj1 = {'val1': 1};
    let obj2 = {'val2': 3};
  
    // Checking of operands
    console.log(obj1.val1 < 10);        
    console.log(obj1 < obj2);
    console.log(obj1.val1 < obj2.val2);
    console.log(obj2 < obj1);
    console.log(obj2.val2 < obj1.val1);
</script>

Output:

> true
> false
> true
> false
> false

Less than or equal operator (<=): This operator is used to checks whether the left side operand value is less than or equal to the right side operand value. If yes then the condition is true otherwise false.

Syntax:

x <= y

Below examples illustrate the (<=) operator in JavaScript:

Example 1:

<script>
    // Illustration of (<=) operator
    let val1 = 5;
    let val2 = "5";
  
    // Checking of operands
    console.log(val1 <= 15);
    console.log(val2 <= "0");        
    console.log(val1 <= "0");
    console.log(val2 <= 15);
</script>

Output:

> true
> false
> false
> true

Example 2:

<script>
    // Illustration of (<=) operator
    let obj1 = {'val1': 1};
    let obj2 = {'val2': 3};
  
    // Checking of operands
    console.log(obj1.val1 <= 10);        
    console.log(obj1 <= obj2);
    console.log(obj1.val1 <= obj2.val2);
    console.log(obj2 <= obj1);
    console.log(obj2.val2 <= obj1.val1);
</script>