Javascript Array isArray()

Introduction

The Array.isArray() method checks whether the passed value is an Array. 

Array.isArray(value)
  • value - The value to be checked.
let a = Array.isArray([1, 2, 3]);
console.log(a);// true
a = Array.isArray({foo: 123}); //from w ww . j av a  2  s .  c o m
console.log(a);// false
a = Array.isArray('foobar');
console.log(a);// false
a = Array.isArray(undefined);
console.log(a);// false

// all following calls return true
console.log(Array.isArray([]));
console.log(Array.isArray([1]));
console.log(Array.isArray(new Array()));
console.log(Array.isArray(new Array('a', 'b', 'c', 'd')));
console.log(Array.isArray(new Array(3)));
console.log(Array.isArray(Array.prototype)); 

// all following calls return false
console.log(Array.isArray());
console.log(Array.isArray({}));
console.log(Array.isArray(null));
console.log(Array.isArray(undefined));
console.log(Array.isArray(42));
console.log(Array.isArray('Array'));
console.log(Array.isArray(true));
console.log(Array.isArray(false));
console.log(Array.isArray(new Uint8Array(32)));



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