JavaScript Array.every()

every() Syntax

The syntax of the every() method is:

arr.every(callback(currentValue), thisArg)

Here, arr is an array.

every() Parameters

The every() method takes in:

• callback() - the function to test for each array element. It takes in:
  • currentValue - the current element being passed from the array.
• thisArg (optional) - value to use as this when executing callback(). By default, it is undefined.

every() Return Value

The every() method returns:

• true - if all the array elements pass the given test function (callback returns a truthy value).
• false - if any array element fails the given test function.

Example 1: Check if Array Elements Are Even

In the above example, we have created the checkEven() function that checks whether a given number is even or not.

We then call the every() method on the numbers array. Since there is an odd number (7) in the array, we get false as an output.

Example 2: JavaScript every() With Arrow Function

In the above example, we have created the numbers array. Then, we call the every() method on that array.

Notice the arrow function element=> element < 6 inside the every() method. This function checks whether a given array element is less than 6 or not.

Since, all the elements in the numbers array are less than 6, we get true as an output.

Recommended Reading:

• JavaScript Array some()