make a string of length js code example

Example 1: js fill string with n characters

var str = new Array(len + 1).join( character );

Example 2: How to get length of string in javascript without using native length method

var str = userInput[0];
  var count = 0;
  while(str[count] !== undefined)
  {
      count += 1;
  }
  console.log(count)