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 isundefined
.
Return value from every()
- Returns
true
if all array elements pass the given test function (callback
returns a truthy value). - Otherwise, it returns
false
.
Notes:
every()
does not change the original array.every()
does not executecallback
for array elements without values.
Example: Check Value of Array Element
function checkAdult(age) {
return age >= 18;
}
const ageArray = [34, 23, 20, 26, 12];
let check = ageArray.every(checkAdult); // false
if (!check) {
console.log("All members must be at least 18 years of age.")
}
// using arrow function
let check1 = ageArray.every(age => age >= 18); // false
console.log(check1);
Output
All members must be at least 18 years of age. false
Recommended Reading: JavaScript Array some()