every method

The every method checks array elements according to a passed function. The method returns true if the passed function returns true for all array elements, otherwise the method returns false.

You can pass three parameters to the function. If these parameters are present (they are not required), then the first one will automatically get the array element, the second one will get its number in the array (index), and the third one will get the array itself.

Syntax

array.every(function(element, index, array) {
	return true or false;
});

Example

We check that all elements in an array of numbers are positive:

let arr = [1, 2, 3, 4, 5];

let check = arr.every(function(elem) {
	if (elem >= 0) {
		return true;
	} else {
		return false;
	}
});

console.log(check);

The code execution result:

true

Example

Let's check that the product of an element and its index is always less than 30:

let arr = [1, 2, 3, 4, 5];

let check = arr.every(function(elem, index) {
	if (elem * index < 30) {
		return true;
	} else {
		return false;
	}
});

console.log(check);

The code execution result:

true

Example

If necessary, an array itself can be passed to the third parameter:

let check = arr.every(function(elem, index, arr) {
	array arr will be available here
});

every method

Syntax

Example

Example

Example

See also