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Check if a number is odd or even using Javascript

There are multiple ways in Javascript to check if a given value is even or odd. We will be explaining the methods one by one in this post.
const value = 6;

const is_even = value % 2 == 0;

if (is_even) {
    console.log("Value is an even number");
} else {
    console.log("Value is an odd number");
}
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Output

Value is an even number

Try it yourself

We are finding the mod of a number after dividing it by 2. If the mod is equal to 0 then the number is even and if it does not equal to 0, the number is odd.

# Example 2

function check_value(value) { return value % 2 == 0 ? "even" : "odd"; }

console.log("Value 10 is: " + check_value(10));
console.log("Value 11 is: " + check_value(11));
console.log("Value 12 is: " + check_value(12));
console.log("Value 13 is: " + check_value(13));
console.log("Value 14 is: " + check_value(14));

Output

Value 10 is: even
Value 11 is: odd
Value 12 is: even
Value 13 is: odd
Value 14 is: even

Try it yourself

Check if a number is even or odd using AND operator

We can also use the AND(&) operator of Javascript to check whether a given number is even or odd. We have created a function check_val here that will be taking the value as a parameter. Inside the check_val() function, we are using AND operator inside and returning odd or even based on the given value.

// Check if a number is even or odd using AND operator
function check_val(val) {
    return (val & 1) ? "odd" : "even";
}

console.log("Value 10 is: " + check_val(10));
console.log("Value 11 is: " + check_val(11));
console.log("Value 12 is: " + check_val(12));
console.log("Value 13 is: " + check_val(13));
console.log("Value 14 is: " + check_val(14));

Output

Value 10 is: even
Value 11 is: odd
Value 12 is: even
Value 13 is: odd
Value 14 is: even

Try it yourself

Using ES6 

If you are creating your application using ES6 then you can check the number for odd and even values with one line of code. 

const is_odd = val => val % 2 == 1;

console.log(is_odd(3));
console.log(is_odd(4));

Output

true
false

Try it yourself

In the above code example, we have created a function is_odd using ES6. It takes the number as a parameter and returns true if the value is odd and false if the value is even.

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