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isFinite()

Baseline

20157

isFinite() isFinite() NaN Infinity isFinite() Number.isFinite() 

function div(x) {
  if (isFinite(1000 / x)) {
    return "Number is NOT Infinity.";
  }
  return "Number is Infinity!";
}

console.log(div(0));
// : "Number is Infinity!""

console.log(div(1));
// : "Number is NOT Infinity."

js
isFinite(value)

value

NaNInfinity-Infinity false true

isFinite()

isFinite() NaN Infinity isNaN isFinite("1") true

Number.isFinite() false

isFinite

js
isFinite(Infinity); // false
isFinite(NaN); // false
isFinite(-Infinity); // false

isFinite(0); // true
isFinite(2e64); // true
isFinite(910); // true

//  Number.isFinite() 
isFinite(null); // true
isFinite("0"); // true

ECMAScript 2027 LanguageSpecification
# sec-isfinite-number

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