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# JavaScript Comparison and Logical Operators

Comparison and Logical operators are used to test for true or false.

## Comparison Operators

Comparison operators are used in logical statements to determine equality or difference between variables or values.

Given that x = 5, the table below explains the comparison operators:

Operator Description Comparing Returns Try it
== equal to x == 8 false Try it »
x == 5 true Try it »
x == "5" true Try it »
=== equal value and equal type x === 5 true Try it »
x === "5" false Try it »
!= not equal x != 8 true Try it »
!== not equal value or not equal type x !== 5 false Try it »
x !== "5" true Try it »
x !== 8 true Try it »
> greater than x > 8 false Try it »
< less than x < 8 true Try it »
>= greater than or equal to x >= 8 false Try it »
<= less than or equal to x <= 8 true Try it »

## How Can it be Used

Comparison operators can be used in conditional statements to compare values and take action depending on the result:

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

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

## Logical Operators

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

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

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

## Conditional (Ternary) Operator

JavaScript also contains a conditional operator that assigns a value to a variable based on some condition.

### Syntax

variablename = (condition) ? value1:value2

### Example

var voteable = (age < 18) ? "Too young":"Old enough";
Try it Yourself »

If the variable age is a value below 18, the value of the variable voteable will be "Too young", otherwise the value of voteable will be "Old enough".

## Comparing Different Types

Comparing data of different types may give unexpected results.

When comparing a string with a number, JavaScript will convert the string to a number when doing the comparison. An empty string converts to 0. A non-numeric string converts to NaN which is always false.

Case Value Try
2 < 12 true Try it »
2 < "12" true Try it »
2 < "John" false Try it »
2 > "John" false Try it »
2 == "John" false Try it »
"2" < "12" false Try it »
"2" > "12" true Try it »
"2" == "12" false Try it »

When comparing two strings, "2" will be greater than "12", because (alphabetically) 1 is less than 2.

To secure a proper result, variables should be converted to the proper type before comparison:

age = Number(age);
if (isNaN(age)) {
voteable = "Error in input";
} else {
voteable = (age < 18) ? "Too young" : "Old enough";
}
Try it Yourself »

## JavaScript Bitwise Operators

Bit operators work on 32-bit numbers.

Any numeric operand in the operation is converted into a 32-bit number.

The result is converted back to a JavaScript number.

### Example

x = 5 & 1;

The result in x:

1
Try it Yourself »

Operator Description Example Same as Result Decimal
& AND x = 5 & 1 0101 & 0001 0001 1
| OR x = 5 | 1 0101 | 0001 0101 5
~ NOT x = ~ 5  ~0101 1010 10
^ XOR x = 5 ^ 1 0101 ^ 0001 0100 4
<< Left shift x = 5 << 1 0101 << 1 1010 10
>> Right shift x = 5 >> 1 0101 >> 1 0010 2 The examples above use 4 bits unsigned examples. But JavaScript uses 32-bit signed numbers. Because of this, in JavaScript, ~ 5 will not return 10. It will return -6. ~00000000000000000000000000000101 will return 11111111111111111111111111111010