Remove All Occurrence of a substring

Exercise 1

Write a function that takes a string and a substring as parameters
If the substring parameter value is found on the main string parameter then remove the substring value on main string and print new string in console.

   
function removeSubstring(mainString, subString) {
  const result = mainString.split(subString).join('');
  console.log(result);
}

removeSubstring("This is a test string", "is") ;