Generate a random string with a fixed length

genrandstr.js

function genRandStr(length = 41){
  // Math.random returns number with length between 16 and 18 chars
  // if length below 16 do in one go
  if (length <= 16) {
    return Math.random().toString(36).substring(2,length+2);
  }

  // else calculate how many iterations we need
  const iterations = Math.ceil(length / 16);
  let outputStr = '';

  for(let i = 0; i < iterations; i++){
    outputStr += Math.random().toString(36).substring(2,18);
  }

  // correct length if it's too high
  if(outputStr.length > length) {
    outputStr = outputStr.substring(0,length);
  }

  return outputStr;
}