sentenceCase.js

function titleCase(str) {
  var words = str.split(" ");
  
  for(var i = 0; i < words.length; i++){
    
    var temp = words[i].split("");
    for(var j = 0; j < temp.length; j++){
      
      if(j === 0){
        temp[j] = temp[j].toUpperCase();
      } else{
        temp[j] = temp[j].toLowerCase();
      }
      
    }
    
    words[i] = temp.join("");
  }
  
  str = words.join(" ");
  
  return str;
}