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# JavaScript - Math.sign() method example

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`Math` `sign` is static method that takes only one parameter and returns number that represents its signum.

``````// ONLINE-RUNNER:browser;

console.log( Math.sign( -0 ) ); // +0
console.log( Math.sign( +0 ) ); // -0
console.log( Math.sign( -1 ) ); // -1
console.log( Math.sign( +1 ) ); // +1
console.log( Math.sign( -100 ) ); // -1
console.log( Math.sign( +100 ) ); // +1
console.log( Math.sign( -Infinity ) ); // -1
console.log( Math.sign( +Infinity ) ); // +1
console.log( Math.sign( NaN ) ); // NaN``````

## 1. Documentation

 Syntax `Math.sign(number)` Parameters `number` - integer or float number value (primitive value). Result Returns `-1`, `-0`, `+0`, `+1`, `NaN` for negarive, negative zero, positive zero, positive numbers. If operation can not be executed it returns `NaN`. Description `sign` is static method that takes only one parameter and returns number that represents its signum.

Note: this method has been added in ECMAScript 2015.

## 2. Polyfil method example

``````// ONLINE-RUNNER:browser;

// Polyfil method
if (!Math.sign) {
Math.sign = function(x, y) {
if (x === 0 || x !== x) {
return x;
}

return x > 0 ? 1 : -1;
};
}

// Example:

console.log( Math.sign( -0 ) ); // +0
console.log( Math.sign( +0 ) ); // -0
console.log( Math.sign( -1 ) ); // -1
console.log( Math.sign( +1 ) ); // +1
console.log( Math.sign( -100 ) ); // -1
console.log( Math.sign( +100 ) ); // +1
console.log( Math.sign( -Infinity ) ); // -1
console.log( Math.sign( +Infinity ) ); // +1
console.log( Math.sign( NaN ) ); // NaN``````