javascript模拟实现C# String.format函数功能代码

String.format = function ()
        {
            var formatStr = arguments[0];

            if ( typeof formatStr === 'string' )
            {
                var pattern,
                    length = arguments.length;

                for ( var i = 1; i < length; i++ )
                {
                    pattern = new RegExp( '\\{' + ( i - 1 ) + '\\}', 'g' );
                    formatStr = formatStr.replace( pattern, arguments[i] );
                }
            } else
            {
                formatStr = '';
            }

            return formatStr;
        };

String.format('http://wcf.open.a.com/blog/sitehome/paged/{0}/{1}',1,20)
输出： "http://wcf.open.a.com/blog/sitehome/paged/1/20"

String.format('{0}+{0}+{1}={2}',1,2,1+1+2)
输出: "1+1+2=4"

String.format({name:'leonwang'},'hello,world')
输出: ""