string.extensions.js

/*
 * StringExtensions
 * http://www.karalamalar.net/
 *
 * Copyright (c) 2009-2013 İzzet Emre Erkan
 * Licensed under Creative Commons Attribution-Share Alike 3.0 Unported License
 * http://creativecommons.org/licenses/by-sa/3.0/
 */
String.prototype.trimLeft = function (character) {
  character = character || ' ';
  return this.replace(new RegExp('^[' + character + ']+'), "");
};

String.prototype.trimRight = function (character) {
  character = character || ' ';
  return this.replace(new RegExp('[' + character + ']+$'), "");
};

String.prototype.trim = function (character) {
  return this.trimLeft(character).trimRight(character);
};

String.prototype.padLeft = function (length, character) {
  var t = this.toString();
  character = character || ' ';
  while (t.length < length) {
    t = character + t;
  }
  return t;
};

String.prototype.padRight = function (length, character) {
  var t = this.toString();
  character = character || ' ';
  while (t.length < length) {
    t = t + character;
  }
  return t;
};

String.prototype.insert = function (position, character) {
  var t = this.toString();
  return t.substring(0, position) + character + t.substring(position);
};

String.prototype.startsWith = function (text) {
  return this.match('^' + text) == text;
};

String.prototype.endsWith = function (character) {
  return this.match(character + '$') == character;
};

String.prototype.isNullOrEmpty = function () {
  return this === null || this.length === 0;
};

String.prototype.isNullOrWhitespace = function () {
  return this === null || this.replace(/\s/g, '').length === 0;
};

String.prototype.append = function (text, count) {
  var t = this.toString();
  count = count || 1;
  while (0 < count) {
    t = t + text;
    count--;
  }
  return t;
};

String.prototype.appendTo = function (text, count) {
  var t = this.toString();
  return text.append(t, count);
};

String.prototype.prepend = function (text, count) {
  var t = this.toString();
  count = count || 1;
  while (0 < count) {
    t = text + t;
    count--;
  }
  return t;
};

String.prototype.prependTo = function (text, count) {
  var t = this.toString();
  return text.prepend(t, count);
};

// More info: https://github.com/karalamalar/valiDate
String.prototype.valiDate = function () {
  if (/^(0?[1-9]|[12][0-9]|3[01])[- /.](0?[1-9]|1[012])[- /.](19|20)[0-9]{2}$/.test(this)) {
    var v = this.replace(/[- /]/g, '.').split('.'),
      d = parseInt(v[0], 10),
      m = parseInt(v[1], 10),
      y = parseInt(v[2], 10),
      o = new Date(y, m - 1, d);
    return o.getDate() === d && o.getMonth() + 1 === m && o.getFullYear() === y ? o : false;
  } else {
    return false;
  }
};