JavaScript forEach() function with an array used to execute a function on each item in an array. This method calls a function for each element in an array if the array is not empty.
array.forEach(function(currentValue, index, arr), thisValue)Example Array forEach JavaScript
Simple HTML example code.
<!DOCTYPE html>
<html>
<head>
  <script>
    const array1 = ['a', 'b', 'c'];
    array1.forEach(element => console.log(element));
  </script>
</head>
<body>
</body>
</html>
Output:

More example
Get the sum of a given number
  <script>
    let sum = 0;
    const numbers = [10, 20, 30];
    numbers.forEach(myFunction);
    function myFunction(item) {
      sum += item;
    }
    console.log(sum)
  </script>Output: 60
Multiply each element of the array by 10:
  <script>
    let sum = 0;
    const numbers = [10, 20, 30];
    numbers.forEach(myFunction);
    function myFunction(item, index, arr) {
      arr[index] = item * 10;
    } 
    console.log(numbers)
  </script>Output: Array(3) [ 100, 200, 300 ]
Do comment if you have any doubts or suggestions on this JS Array topic.
Note: The All JS Examples codes are tested on the Firefox browser and the Chrome browser.
OS: Windows 10
Code: HTML 5 Version