Nodejs String Format format(args)

Method Source Code

/**//w w  w  .  j a va 2 s  . c o  m
 * Add a format method to the prototype of String Class
 * Inorder to achieve python's format method functionality
 *
 * Usage - 
 * var formattedString = "hi $0 $1 $2 $3.".format(["pk", "bk", "ck", "dk"]); //hi pk, bk, ck, dk
 *
 * @param {array} [args] [list of strings, that has to be replaced]
 * @return {string} Returns the string with replaced text.
 */

String.prototype.format = function(args){

  var str = this.toString(),
      result = str.match(/\$[0-9]+/gi),
      mapper = {};
  
  
  if(args.length < result.length)
    throw new Error("Index out of range.");
  
  
  for(var i = 0; i < result.length; i++){
    //create a mapper
    mapper[result[i]] = args[parseInt(result[i].replace("$", ""), 10)]
  }
  
  for(var i = 0; i < result.length; i++){
    str = str.replace(result[i], mapper[result[i]]);
  }

  
  return str; 
};

Related

1. format(args)

   String.prototype.format = function (args) {
     var str = this;
     return str.replace(String.prototype.format.regex, function(item) {
       var intVal = parseInt(item.substring(1, item.length - 1));
       var replace;
       if (intVal >= 0) {
         replace = args[intVal];
       } else if (intVal === -1) {
         replace = "{";
   ...
   

2. format(args)

   'use strict';
   String.prototype.format = function (args) {
     if (arguments.length > 0) {
       var result = this;
       if (arguments.length == 1 && typeof (args) == "object") {
         for (var key in args) {
           result = result.replace(new RegExp("({" + key + "})", "g"), args[key]);
       else {
         for (var i = 0; i < arguments.length; i++) {
           if (arguments[i] == undefined) {
             return "";
           else {
             var reg = new RegExp("({[" + i + "]})", "g");
             result = result.replace(reg, arguments[i]);
       return result;
     else {
       return this;
   };
   

3. format(args)

   String.prototype.format = function(args) {
       var result = this;
       if (arguments.length > 0) {    
           if (arguments.length == 1 && typeof (args) == "object") {
               for (var key in args) {
                   if(args[key]!=undefined){
                       var reg = new RegExp("({" + key + "})", "g");
                       result = result.replace(reg, args[key]);
           else {
               for (var i = 0; i < arguments.length; i++) {
                   if (arguments[i] != undefined) {
                       var reg = new RegExp("({[" + i + "]})", "g");
                       result = result.replace(reg, arguments[i]);
       return result;
   

4. format(args)

   String.prototype.format = function (args) {
       var result = this;
       if (arguments.length > 0) {
           if (arguments.length == 1 && typeof (args) == "object") {
               for (var key in args) {
                   if (args[key] != undefined) {
                       var reg = new RegExp("({" + key + "})", "g");
                       result = result.replace(reg, args[key]);
           else {
               for (var i = 0; i < arguments.length; i++) {
                   if (arguments[i] != undefined) {
                       var reg = new RegExp("({)" + i + "(})", "g");
                       result = result.replace(reg, arguments[i]);
       return result;
   

5. format(args)

   String.prototype.format = function(args) {
       var result = this;
       if (arguments.length > 0) {    
           if (arguments.length == 1 && typeof (args) == "object") {
               for (var key in args) {
                   if(args[key]!=undefined){
                       var reg = new RegExp("({" + key + "})", "g");
                       result = result.replace(reg, args[key]);
           else {
               for (var i = 0; i < arguments.length; i++) {
                   if (arguments[i] != undefined) {
                       var reg = new RegExp("({[" + i + "]})", "g");
                       result = result.replace(reg, arguments[i]);
       return result;
   

6. format(args)

   String.prototype.format = function(args) {
       var result = this;
       if (arguments.length > 0) {    
           if (arguments.length == 1 && typeof (args) == "object") {
               for (var key in args) {
                   if(args[key]!=undefined){
                       var reg = new RegExp("({" + key + "})", "g");
                       result = result.replace(reg, args[key]);
           else {
               for (var i = 0; i < arguments.length; i++) {
                   if (arguments[i] != undefined) {
                       var reg= new RegExp("({)" + i + "(})", "g");
                       result = result.replace(reg, arguments[i]);
       return result;
   

7. format(args)

   function valPhone(phoneNumber) {
       if (!/^(13[0-9]|14[0-9]|15[0-9]|18[0-9])\d{8}$/i.test(phoneNumber)) {
           return false;
       } else {
           return true;
   String.prototype.format = function(args) {
       if (arguments.length>0) {
   ...
   

8. format(args)

   String.prototype.format = function (args) {
       var str = this;
       return str.replace(String.prototype.format.regex, function (item) {
           var intVal = parseInt(item.substring(1, item.length - 1));
           var replace;
           if (intVal >= 0) {
               replace = args[intVal];
           } else if (intVal === -1) {
               replace = "{";
   ...
   

9. format(args)

   'use strict';
   String.prototype.format = function (args) {
       if (arguments.length>0) {
           var result = this;
           console.log(this)
           if (arguments.length ==1 && typeof(args)=="object") {
               for(var key in args){
                   var reg = new RegExp ("({"+key+"})","g");
                   result = result.replace(reg,args[key]);
   ...