function str_replace (search, replace, subject, count) {
    // Replaces all occurrences of search in haystack with replace  
    // 
    // version: 909.322
    // discuss at: http://phpjs.org/functions/str_replace
    // +   original by: Kevin van Zonneveld (http://kevin.vanzonneveld.net)
    // +   improved by: Gabriel Paderni
    // +   improved by: Philip Peterson
    // +   improved by: Simon Willison (http://simonwillison.net)
    // +    revised by: Jonas Raoni Soares Silva (http://www.jsfromhell.com)
    // +   bugfixed by: Anton Ongson
    // +      input by: Onno Marsman
    // +   improved by: Kevin van Zonneveld (http://kevin.vanzonneveld.net)
    // +    tweaked by: Onno Marsman
    // +      input by: Brett Zamir (http://brett-zamir.me)
    // +   bugfixed by: Kevin van Zonneveld (http://kevin.vanzonneveld.net)
    // +   input by: Oleg Eremeev
    // +   improved by: Brett Zamir (http://brett-zamir.me)
    // +   bugfixed by: Oleg Eremeev
    // %          note 1: The count parameter must be passed as a string in order
    // %          note 1:  to find a global variable in which the result will be given
    // *     example 1: str_replace(' ', '.', 'Kevin van Zonneveld');
    // *     returns 1: 'Kevin.van.Zonneveld'
    // *     example 2: str_replace(['{name}', 'l'], ['hello', 'm'], '{name}, lars');
    // *     returns 2: 'hemmo, mars'
    var i = 0, j = 0, temp = '', repl = '', sl = 0, fl = 0,
            f = [].concat(search),
            r = [].concat(replace),
            s = subject,
            ra = r instanceof Array, sa = s instanceof Array;
    s = [].concat(s);
    if (count) {
        this.window[count] = 0;
    }

    for (i=0, sl=s.length; i < sl; i++) {
        if (s[i] === '') {
            continue;
        }
        for (j=0, fl=f.length; j < fl; j++) {
            temp = s[i]+'';
            repl = ra ? (r[j] !== undefined ? r[j] : '') : r[0];
            s[i] = (temp).split(f[j]).join(repl);
            if (count && s[i] !== temp) {
                this.window[count] += (temp.length-s[i].length)/f[j].length;}
        }
    }
    return sa ? s : s[0];
}




function trim (str, charlist) {
    // Strips whitespace from the beginning and end of a string  
    // 
    // version: 909.322
    // discuss at: http://phpjs.org/functions/trim
    // +   original by: Kevin van Zonneveld (http://kevin.vanzonneveld.net)
    // +   improved by: mdsjack (http://www.mdsjack.bo.it)
    // +   improved by: Alexander Ermolaev (http://snippets.dzone.com/user/AlexanderErmolaev)
    // +      input by: Erkekjetter
    // +   improved by: Kevin van Zonneveld (http://kevin.vanzonneveld.net)
    // +      input by: DxGx
    // +   improved by: Steven Levithan (http://blog.stevenlevithan.com)
    // +    tweaked by: Jack
    // +   bugfixed by: Onno Marsman
    // *     example 1: trim('    Kevin van Zonneveld    ');
    // *     returns 1: 'Kevin van Zonneveld'
    // *     example 2: trim('Hello World', 'Hdle');
    // *     returns 2: 'o Wor'
    // *     example 3: trim(16, 1);
    // *     returns 3: 6
    var whitespace, l = 0, i = 0;
    str += '';
    
    if (!charlist) {
        // default list
        whitespace = " \n\r\t\f\x0b\xa0\u2000\u2001\u2002\u2003\u2004\u2005\u2006\u2007\u2008\u2009\u200a\u200b\u2028\u2029\u3000";
    } else {
        // preg_quote custom list
        charlist += '';
        whitespace = charlist.replace(/([\[\]\(\)\.\?\/\*\{\}\+\$\^\:])/g, '$1');
    }
    
    l = str.length;
    for (i = 0; i < l; i++) {
        if (whitespace.indexOf(str.charAt(i)) === -1) {
            str = str.substring(i);
            break;
        }
    }
    
    l = str.length;
    for (i = l - 1; i >= 0; i--) {
        if (whitespace.indexOf(str.charAt(i)) === -1) {
            str = str.substring(0, i + 1);
            break;
        }
    }
    
    return whitespace.indexOf(str.charAt(0)) === -1 ? str : '';
}





function explode (delimiter, string, limit) {
    // Splits a string on string separator and return array of components. If limit is positive only limit number of components is returned. If limit is negative all components except the last abs(limit) are returned.  
    // 
    // version: 909.322
    // discuss at: http://phpjs.org/functions/explode
    // +     original by: Kevin van Zonneveld (http://kevin.vanzonneveld.net)
    // +     improved by: kenneth
    // +     improved by: Kevin van Zonneveld (http://kevin.vanzonneveld.net)
    // +     improved by: d3x
    // +     bugfixed by: Kevin van Zonneveld (http://kevin.vanzonneveld.net)
    // *     example 1: explode(' ', 'Kevin van Zonneveld');
    // *     returns 1: {0: 'Kevin', 1: 'van', 2: 'Zonneveld'}
    // *     example 2: explode('=', 'a=bc=d', 2);
    // *     returns 2: ['a', 'bc=d']
 
    var emptyArray = { 0: '' };
    
    // third argument is not required
    if ( arguments.length < 2 ||
        typeof arguments[0] == 'undefined' ||
        typeof arguments[1] == 'undefined' )
    {
        return null;
    }
 
    if ( delimiter === '' ||
        delimiter === false ||
        delimiter === null )
    {
        return false;
    }
 
    if ( typeof delimiter == 'function' ||
        typeof delimiter == 'object' ||
        typeof string == 'function' ||
        typeof string == 'object' )
    {
        return emptyArray;
    }
 
    if ( delimiter === true ) {
        delimiter = '1';
    }
    
    if (!limit) {
        return string.toString().split(delimiter.toString());
    } else {
        // support for limit argument
        var splitted = string.toString().split(delimiter.toString());
        var partA = splitted.splice(0, limit - 1);
        var partB = splitted.join(delimiter.toString());
        partA.push(partB);
        return partA;
    }
}



function ceil (value) {
    // Returns the next highest integer value of the number  
    // 
    // version: 909.322
    // discuss at: http://phpjs.org/functions/ceil
    // +   original by: Onno Marsman
    // *     example 1: ceil(8723321.4);
    // *     returns 1: 8723322
    return Math.ceil(value);
}


function strtolower (str) {
    // Makes a string lowercase  
    // 
    // version: 908.406
    // discuss at: http://phpjs.org/functions/strtolower
    // +   original by: Kevin van Zonneveld (http://kevin.vanzonneveld.net)
    // +   improved by: Onno Marsman
    // *     example 1: strtolower('Kevin van Zonneveld');
    // *     returns 1: 'kevin van zonneveld'
    return (str+'').toLowerCase();
}


function strlen (string) {
    // Get string length  
    // 
    // version: 908.406
    // discuss at: http://phpjs.org/functions/strlen
    // +   original by: Kevin van Zonneveld (http://kevin.vanzonneveld.net)
    // +   improved by: Sakimori
    // +      input by: Kirk Strobeck
    // +   improved by: Kevin van Zonneveld (http://kevin.vanzonneveld.net)
    // +   bugfixed by: Onno Marsman
    // +    revised by: Brett Zamir (http://brett-zamir.me)
    // %        note 1: May look like overkill, but in order to be truly faithful to handling all Unicode
    // %        note 1: characters and to this function in PHP which does not count the number of bytes
    // %        note 1: but counts the number of characters, something like this is really necessary.
    // *     example 1: strlen('Kevin van Zonneveld');
    // *     returns 1: 19
    // *     example 2: strlen('A\ud87e\udc04Z');
    // *     returns 2: 3
    var str = string+'';
    var i = 0, chr = '', lgth = 0;

    var getWholeChar = function (str, i) {
        var code = str.charCodeAt(i);
        var next = '', prev = '';
        if (0xD800 <= code && code <= 0xDBFF) { // High surrogate (could change last hex to 0xDB7F to treat high private surrogates as single characters)
            if (str.length <= (i+1))  {
                throw 'High surrogate without following low surrogate';
            }
            next = str.charCodeAt(i+1);
            if (0xDC00 > next || next > 0xDFFF) {
                throw 'High surrogate without following low surrogate';
            }
            return str.charAt(i)+str.charAt(i+1);
        } else if (0xDC00 <= code && code <= 0xDFFF) { // Low surrogate
            if (i === 0) {
                throw 'Low surrogate without preceding high surrogate';
            }
            prev = str.charCodeAt(i-1);
            if (0xD800 > prev || prev > 0xDBFF) { //(could change last hex to 0xDB7F to treat high private surrogates as single characters)
                throw 'Low surrogate without preceding high surrogate';
            }
            return false; // We can pass over low surrogates now as the second component in a pair which we have already processed
        }
        return str.charAt(i);
    };

    for (i=0, lgth=0; i < str.length; i++) {
        if ((chr = getWholeChar(str, i)) === false) {
            continue;
        } // Adapt this line at the top of any loop, passing in the whole string and the current iteration and returning a variable to represent the individual character; purpose is to treat the first part of a surrogate pair as the whole character and then ignore the second part
        lgth++;
    }
    return lgth;
}


function substr (f_string, f_start, f_length) {
    // Returns part of a string  
    // 
    // version: 908.406
    // discuss at: http://phpjs.org/functions/substr
    // +     original by: Martijn Wieringa
    // +     bugfixed by: T.Wild
    // +      tweaked by: Onno Marsman
    // *       example 1: substr('abcdef', 0, -1);
    // *       returns 1: 'abcde'
    // *       example 2: substr(2, 0, -6);
    // *       returns 2: ''
    f_string += '';

    if (f_start < 0) {
        f_start += f_string.length;
    }

    if (f_length == undefined) {
        f_length = f_string.length;
    } else if (f_length < 0){
        f_length += f_string.length;
    } else {
        f_length += f_start;
    }

    if (f_length < f_start) {
        f_length = f_start;
    }

    return f_string.substring(f_start, f_length);
}

function in_array (needle, haystack, argStrict) {
    // Checks if the given value exists in the array  
    // 
    // version: 908.406
    // discuss at: http://phpjs.org/functions/in_array
    // +   original by: Kevin van Zonneveld (http://kevin.vanzonneveld.net)
    // +   improved by: vlado houba
    // *     example 1: in_array('van', ['Kevin', 'van', 'Zonneveld']);
    // *     returns 1: true
    // *     example 2: in_array('vlado', {0: 'Kevin', vlado: 'van', 1: 'Zonneveld'});
    // *     returns 2: false
    // *     example 3: in_array(1, ['1', '2', '3']);
    // *     returns 3: true
    // *     example 3: in_array(1, ['1', '2', '3'], false);
    // *     returns 3: true
    // *     example 4: in_array(1, ['1', '2', '3'], true);
    // *     returns 4: false
    var key = '', strict = !!argStrict;

    if (strict) {
        for (key in haystack) {
            if (haystack[key] === needle) {
                return true;
            }
        }
    } else {
        for (key in haystack) {
            if (haystack[key] == needle) {
                return true;
            }
        }
    }

    return false;
}