phpjs/functions/var/settype.js

php.js offers community built php functions in javascript

function settype(vr, type) {
  // From: http://phpjs.org/functions
  // +   original by: Waldo Malqui Silva
  // +   improved by: Kevin van Zonneveld (http://kevin.vanzonneveld.net)
  // +    revised by: Brett Zamir (http://brett-zamir.me)
  // %        note 1: Credits to Crockford also
  // %        note 2: only works on global variables, and "vr" must be passed in as a string
  // *     example 1: foo = '5bar';
  // *     example 1: settype('foo', 'integer');
  // *     example 1: $result = foo
  // *     returns 1: 5
  // *     example 2: foo = true;
  // *     example 2: settype('foo', 'string');
  // *     example 2: $result = foo
  // *     returns 2: '1'

  var is_array = function(arr) {
    return typeof arr === 'object' && typeof arr.length === 'number' && !(arr.propertyIsEnumerable('length')) && typeof arr.splice === 'function';
  };
  var v, mtch, i, obj;
  v = this[vr] ? this[vr] : vr;

  try {
    switch (type) {
      case 'boolean':
        if (is_array(v) && v.length === 0) {
          this[vr] = false;
        } else if (v === '0') {
          this[vr] = false;
        } else if (typeof v === 'object' && !is_array(v)) {
          var lgth = false;
          for (i in v) {
            lgth = true;
          }
          this[vr] = lgth;
        } else {
          this[vr] = !! v;
        }
        break;
      case 'integer':
        if (typeof v === 'number') {
          this[vr] = parseInt(v, 10);
        } else if (typeof v === 'string') {
          mtch = v.match(/^([+\-]?)(\d+)/);
          if (!mtch) {
            this[vr] = 0;
          } else {
            this[vr] = parseInt(v, 10);
          }
        } else if (v === true) {
          this[vr] = 1;
        } else if (v === false || v === null) {
          this[vr] = 0;
        } else if (is_array(v) && v.length === 0) {
          this[vr] = 0;
        } else if (typeof v === 'object') {
          this[vr] = 1;
        }

        break;
      case 'float':
        if (typeof v === 'string') {
          mtch = v.match(/^([+\-]?)(\d+(\.\d+)?|\.\d+)([eE][+\-]?\d+)?/);
          if (!mtch) {
            this[vr] = 0;
          } else {
            this[vr] = parseFloat(v, 10);
          }
        } else if (v === true) {
          this[vr] = 1;
        } else if (v === false || v === null) {
          this[vr] = 0;
        } else if (is_array(v) && v.length === 0) {
          this[vr] = 0;
        } else if (typeof v === 'object') {
          this[vr] = 1;
        }
        break;
      case 'string':
        if (v === null || v === false) {
          this[vr] = '';
        } else if (is_array(v)) {
          this[vr] = 'Array';
        } else if (typeof v === 'object') {
          this[vr] = 'Object';
        } else if (v === true) {
          this[vr] = '1';
        } else {
          this[vr] += '';
        } // numbers (and functions?)
        break;
      case 'array':
        if (v === null) {
          this[vr] = [];
        } else if (typeof v !== 'object') {
          this[vr] = [v];
        }
        break;
      case 'object':
        if (v === null) {
          this[vr] = {};
        } else if (is_array(v)) {
          for (i = 0, obj = {}; i < v.length; i++) {
            obj[i] = v;
          }
          this[vr] = obj;
        } else if (typeof v !== 'object') {
          this[vr] = {
            scalar: v
          };
        }
        break;
      case 'null':
        delete this[vr];
        break;
    }
    return true;
  } catch (e) {
    return false;
  }
}