Nodejs String Format format()

Method Source Code

String.prototype.format = function() {
   var args = arguments;
   //w w w.jav a 2  s  .com
   return this.replace(/\$\{([A-Za-z0-9_]+)\}/g, function(base, element, position) {
      for (var i = 0; i < args.length; i++) {
         if (args[i] != null && typeof(args[i][element]) != "undefined")
            return args[i][element];
      }

      if (typeof(args[element - 1]) == "undefined")
         return base;
      else {
         var elem = args[element - 1];
         
         if (elem === null)
            return "null";
         else
            return elem;
      }
   })
}

Related

1. format()

   String.prototype.format = function() {
       var formattedString = this;
       var strArray = Array.prototype.slice.call(arguments);
       var pattern;
       strArray.forEach(function(value, index) {
           pattern = new RegExp("\\{" + index + "\\}", "g");
           formattedString = formattedString.replace(pattern, value && typeof value === 'string' ? value : '');
       });
       return formattedString;
   ...
   

2. format()

   String.prototype.format = function() {
     var formatted = this;
     for( var arg in arguments ) {
       formatted = formatted.replace("{" + arg + "}", arguments[arg]);
     return formatted;
   };
   

3. format()

   String.prototype.format = function () {
       var formatted = this;
       if (arguments != null) {
           for (var i = 0; i < arguments.length; i++) {
               while (formatted.indexOf("{" + i + "}") > -1) {
                   formatted = formatted.replace("{" + i + "}", arguments[i]);
       return formatted;
   };
   

4. format()

   String.prototype.format = function() {
       var args = arguments;
       return this.replace(/{(\d+)}/g, function(match, number) {
         return typeof args[number] != 'undefined'
           ? args[number]
           : match
           ;
       });
   };
   ...
   

5. format()

   String.prototype.format = function() {
       var res = this;
       for (var i = 0; i < arguments.length; i++) {
           res = res.replace(new RegExp("\\{" + (i) + "\\}", "g"), arguments[i]);
       return res;
   };
   

6. format()

   String.prototype.format = function(){
     var fn = String.format;
     switch (arguments.length) {
       case 1:
         return fn(this, arguments[0]);
       case 2:
         return fn(this, arguments[0], arguments[1]);
       case 3:
         return fn(this, arguments[0], arguments[1], arguments[2]);
   ...
   

7. format()

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

8. format()

   String.prototype.format = function() {
     var args = arguments;
     return this.replace(/{(\d+)}/g, function(match, number) { 
       return typeof args[number] != 'undefined'
         ? args[number]
         : match
       ;
     });
   };
   ...
   

9. format()

   'use strict';
   String.prototype.format = function() {
     var self = this;
     for(var i = 0; i < arguments.length; i += 1) {
       var reg = new RegExp("\\{" + i + "\\}", "gm");
       self = self.replace(reg, arguments[i]);
     return self;
   };
   ...