JavaScript ComparisonandLogical Operators

Comparison and logical operators are used for testingtrueorfalse。

Comparison Operators

Comparison operators are used in logical statements to determine whether variables or values are equal.

x=5The following table explains the comparison operators:
Operator Description Comparison Return value Example
== Equal to x==8 false Example »
x==5 true Example »
=== Strict equal (value and type are equal) x==="5" false Example »
x===5 true Example »
!= Not equal x!=8 true Example »
!== Strict not equal operator (either value or type is not equal, or both are not equal) x!=="5" true Example »
x!==5 false Example »
> Greater than x>8 false Example »
< Less than x<8 true Example »
>= Greater than or equal to x>=8 false Example »
<= Less than or equal to x<=8 true Example »

How to use

You can use comparison operators in conditional statements to compare values, and then take action based on the results:

if (age<18) x="Too young";

You will learn more about conditional statements in the next section of this tutorial.

Logical Operators

Logical operators are used to determine the logic between variables or values.

Given x=6 and y=3, the following table explains the logical operators:

Operator Description Example
&& and (x < 10 && y > 1) is true
|| or (x==5 || y==5) is false
! not !(x==y) is true

Conditional Operator

JavaScript also includes a conditional operator that assigns values to variables based on certain conditions.

Syntax

variablename=(condition)?value1:value2 

Example

Examples

If the value in the variable age is less than 18, assign "Too young" to the variable voteable, otherwise assign "Old enough".

voteable=(age<18)?"Too young":"Old enough";

Try it »
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