JavaScript: Array.prototype.some

By Xah Lee. Date: . Last updated: .
Return true if the function f return true for at least one element. As soon as f return true, exit the iteration and return true. If array is empty, return false.
arrayX can be Array-Like Object.

The function f is passed 3 args:

  1. current_element
  2. current_index
  3. arrayX.
arrayX.some(f, thisArg)
Use thisArg for this Binding of f
const ff = (x => (x === 3));
console.log( [1,2,3,4,5,6].some(ff) ); // true

Use “some” as Loop with Break

some is useful as a forEach with break.

Here is example. Apply f to each element in order. Exit the loop when f returns true.

const ff = (x => { console.log( x ); return x === 3 ; });
// prints
// 1
// 2
// 3

「some」 on Empty Array

some on empty array returns false.

console.log( [].some (x => true) ); // false
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