Nodejs String Format format()

Method Source Code

/**//from   w w w.  j av  a 2  s.  c om
 * String.format function
 *
 * see: http://stackoverflow.com/questions/4974238/javascript-equivalent-of-pythons-format-function
 * usage: "The lazy {} {} over the {}".format("dog", "jumped", "foobar");
 *          outputs:
 *        "The lazy dog jumped over the foobar"
 */
String.prototype.format = function () {
  var i = 0, args = arguments;
  return this.replace(/{(.*?)}/g, function (match, tagInner) {
    replacement = typeof args[i] != 'undefined' ? args[i++] : '';
    if(tagInner == "") {
        return replacement;
    } else {
        var match = tagInner.match(/^:.(\d+)f$/);
        if(match) {
            precision = parseInt(match[1]);
            return parseFloat(replacement).toFixed(precision);
        } else {
            return replacement
        }
    }
  });
};

Related

1. format()

   String.prototype.printf = function (obj) {
     var useArguments = false;
     var _arguments = arguments;
     var i = -1;
     if (typeof _arguments[0] == "string") {
       useArguments = true;
     if (obj instanceof Array || useArguments) {
       return this.replace(/\%s/g,
   ...
   

2. format()

   String.prototype.format = function () {
       'use strict';
       var newString = this;
       function replace(string, search, replacement) {
           return string.replace(new RegExp(search.replace('{', '\\{').replace('}', '\\}'), 'g'), replacement.toString());
       if (arguments[0] !== 'undefined') {
           switch (typeof arguments[0]) {
               case 'object':
   ...
   

3. format()

   String.prototype.format = function() {
     var args = Array.prototype.slice.call(arguments);
     var str = this;
     return str.replace(/%s/g, function(match, index) {
       if (str.charAt(index-1) == "%") {
         return match;
       } else {
         return args.shift();
     });
   

4. format()

   if (!String.prototype.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 args = arguments;
     return this.replace(/\{(\d+)\}/g, function (m, i, o, n) {
       return args[i];
     });
   };
   

6. format()

   String.prototype.format = function() {
       var s = this,
           i = arguments.length;
       while (i--) {
           s = s.replace(new RegExp('\\{' + i + '\\}', 'gm'), arguments[i]);
       return s;
   };
   

7. format()

   String.prototype.format = function () {
       var args = arguments;
       var input = this;        
       var output = "";
       if (input.length > 0) {
           if (args[0] === undefined || args[0] === null) {
               output = "string without any arguments";
           else {
   ...
   

8. format()

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

9. format()

   String.format = function() {
       "use strict"
       var theString = arguments[0];
       for (var i = 1; i < arguments.length; i++) {
           var regEx = new RegExp("\\{" + (i - 1) + "\\}", "gm");
           theString = theString.replace(regEx, arguments[i]);
       return theString;
   };
   ...