对jquery val 获取input 文本框值进行扩展

;(function($,window,document,undefined){
        $.fn.value = function(options) {
                var _selector=this.selector,$this=$(_selector),val;
                if($this.length<=0){
                        var first = _selector.substr(0,1);
                        if("#" === first || "." === first){
                                $this = $(_selector);
                        } else {
                                $this = $("[name='" + _selector + "']");
                        }
                }
                if(options===undefined){
                        if($this.eq(0).is(":radio")) { //单选按钮
                                val =$this.filter(":checked").val();
                        } else if($this.eq(0).is(":checkbox")) { //复选框
                                val='';
                                $this.filter(":checked").each(function(i){
                                        val+=(i==0?'':',')+$(this).val()
                                });
                        } else {
                                val = $this.val();
                        }
                        //判断是否是数值文本框
                        if($this.attr('type')=='number'){
                                if(isNaN(val)){
                                        val=0;
                                }else if(val==''){
                                        val=0;
                                }
                        }
                }else{
                        //判断是否是数值文本框
                        if($this.eq(0).is(":radio")) {
                                $this.filter("[value='" + options + "']").each(function () {
                                        this.checked = true
                                });
                                return true;
                        }else if($this.eq(0).is(":checkbox")){
                                if(!$.isArray(options)&&options&&options.indexOf(',')>0){
                                        $this.val(options.split(','));
                                }
                                return true;
                        }else{
                                $this.val(options);
                        }
                        return true;
                }
                return val;
        }
})(jQuery,window,document);