JavaScript: Array.prototype.some
arrayX.some(f)
-
Return
true
if the function f returntrue
for at least one element. As soon as f returntrue
, exit the iteration and returntrue
. If array is empty, return false.
arrayX can be Array-Like Object.
The function f is passed 3 args:
- currentElement
- currentIndex
- 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 ; }); [1,2,3,4,5,6].some(ff) // prints // 1 // 2 // 3
「some」 on Empty Array
some
on empty array returns false
.
console.log( [].some (x => true) ); // false