String.Format function of JS imitating C #

String.prototype.format2 = function (args) {var s = this, Vals = [], rst = [], pattern =/({|})    /g, Reg = S.match (pattern), Matchs = S.match (/({+[-\w]+}+)/g); if (matchs! = null) {if (Arguments.length > 1) {for (var i = 0, c = arguments.length; i < C; i++                {if (arguments[i]! = undefined) {Vals.push (arguments[i]);        }}}} else if (Object.prototype.toString.call (args) = = = ' [Object Array] ') {vals = args;        } else if (args! = undefined && args! = null) {Vals.push (args);        } var len = vals.length; for (var i = 0, c = matchs.length; i < C; i++) {var _t = matchs[i], _tv = _t.replace (Pattern, '), _r = _t.            Match (pattern); if (_r.length% 2! = 0 | |!/^[0-9]+$/.test (_TV)) {throw new Error (' Input string is not formatted correctly.            ‘);            } var idx = parseint (_TV, 10);                if (idx >= len) {The throw new Error (' zero-based ' index must be greater than or equal to zero and is less than the size of the parameter list.            ‘);            } var _p = S.indexof (_t), _c = _t.match (/{/g). Length, _v = Vals[idx]; if (_v = = null) {throw new Error (' value cannot be null.            ‘);            } var _t1 = _t.replace (/{{/g, ' {'). Replace (/}}/g, '} '); Rst.push (s.substr (0, _p) + (_c > 1?)            (_c% 2! = 0? _t1.replace (' {' + idx + '} ', _v): _T1): _v));        s = s.substr (_p + _t.length);        } rst.push (s);    Return Rst.join ("); } else if (reg! = null && reg.length > 0) {throw new Error (' the input string is not formatted correctly.    ‘); } return s;};

Only basic functionality is implemented

Examples are as follows:

var str = ' (X{{{{0}}} {1}) {2} & X{0} {3} {4}_{5} * (X{0} + {6}) ';

Console.log (STR.FORMAT2 ([7, ' >= ', 123, ' < ', 123, ' K ', ' B ']));

var str = ' Hello: {0}, this is a pseudo C # {1} function written with {0} ';

Console.log (STR.FORMAT2 ([' JS ', ' format ']);
Console.log (STR.FORMAT2 (' JS ', ' format '));

Operation Result:

String.Format function of JS imitating C #