Nodejs Utililty Methods String to Upper Case

String.prototype.toUpper = function() {
  var pattern = /[a-z]/g;
  return this.replace(pattern, function(args) {
    return String.fromCharCode(args.charCodeAt() - 32);
  });
};

String.prototype.toUpper = function(){
  result = this.replace(/[a-z]/g, function(x){
    return x.toUpperCase();
  });
  return result;
};

String.prototype.toUpper = function() {
  return this.replace(/([a-z])/g, function(match){
    return String.fromCharCode(match.charCodeAt(0) - 32);
  });
};

String.prototype.toUpper = function() {
  return this.replace(/[a-z]/g, function(x) {
    return String.fromCharCode(x.charCodeAt(0) - 32);
  });

String.prototype.toUpperCase = function() {
  var s = "";
  for (var i = 0, len = this.length; i < len; i++) {
    var char = this.charCodeAt(i);
    if (char >= 97 && char <= 122) {
      s += String.fromCharCode(char - 32);
    } else {
      s += this[i];
  return s;
};

String.prototype.toUpperCaseFirst = function() {
    return this.charAt(0).toUpperCase() + this.slice(1);
};

String.prototype.toUpperCaseFirst = function() {
    return this[0].toUpperCase() + this.substr(1);
};

String.prototype.toUpperCaseFirst = function() {
  return this.slice(0,1).toUpperCase() + this.slice(1).toLowerCase();
};

window.upperCaseFirstLetter = (str)=>{
  return str.replace(/^\w/, function(w){return w.toUpperCase()});
String.prototype.toUpperCaseFirstLetter = function(){
  return upperCaseFirstLetter(this);

String.prototype.toUpperLowerCase = function() {
    var string = this.split("");
    string[0] = string[0].toUpperCase();
    return string.join("");
};