JSFiddle - React, Tailwind, and code Playground

JavaScript

function checkRepeat(string, search){
  if (!search.length) return 0; 
  var myRe = new RegExp(search, 'g');
  var count = 0;
  while (myRe.exec(string) !== null)
  {
    count++;
    myRe.lastIndex -= search.length-1;
  }
  return count;
}
alert(checkRepeat('ccc','') +'  '+checkRepeat('ccc', 'cc') + ' ' +checkRepeat('cccaacddcccc', 'cc'));