if...else的使用

if语句中一般是某种情况判断是否成立，else中一般存放条件不成立的情况。

else里面最好不要再写if与esle语句了

下面情况不太合适

      if (rows.length == 1) {
    	  if(null!=rows[0].approveState&&rows[0].approveState=="1"){
    		  $Core.UI.message.warning("已提交不可修改！");
    	  }else{ 	
    		  $Core.UI.openDialog("editwind", url + "&"+_self.listOption.idKey+"=" + rows[0][_self.listOption.idKey]+"&type=edit",
    				  {
    			  title: '编辑',
    			  width: '50%',
    			  height: '90%',
    			  onClose: function () {
    				  $dg.datagrid("load");
    			  }
    		});
    	  }
      } else {
          $Core.UI.message.warning("请选择一条记录！");
      }

修改对比

      var url = _self.listOption.formurl+"?s=" + Math.random();
      var rows = $dg.datagrid('getSelections');
      if (rows.length == 1) {
    	  if(rows[0].approveState!="2"&&rows[0].approveState!="3"){ 
    		  if(rows[0].approveState=="0"){
    			  $Core.UI.openDialog("editwind", url + "&"+_self.listOption.idKey+"=" + rows[0][_self.listOption.idKey]+"&type=edit",
    					  {
    				  title: '编辑',
    				  width: '50%',
    				  height: '90%',
    				  onClose: function () {
    					  $dg.datagrid("load");
    				  }
    					  });
    		  }else{ 	
    			  $Core.UI.message.warning("已提交不可修改！");
    		  }
    	  }else{
    		  $Core.UI.message.warning("已审核的数据不可修改！");
    	  }
    	  
      } else {
          $Core.UI.message.warning("请选择一条记录！");
      }
  };

一般if中存放条件成立的语句

    	if(rows[0].approveState =="0"){
    		$.messager.confirm('提示', '您确定执行关闭操作?', function (r) {
    			if (r) {
    				var ids = "";
    				$.each(rows, function (k, j) {
    					ids += (ids == "" ? j[$id] : "," + j[$id]);
    				});
    				var paras = { ids: ids };
    				$.post($url+"/updhstate", paras, function (data) {
    					if (data.code == "0") {
    						$Core.UI.message.success("关闭成功!");
    						$dg.datagrid("load");
    					} else {
    						$Core.UI.message.error(data.msg);
    					}
    				});
    			}
    		});
    	}else{
    		$Core.UI.message.warning("该条数据已经提交！");
    	}

进一步改进最上面的if...else语句

用！替代 ！=

        var rows = $dg.datagrid('getSelections');
        if (rows.length == 1) {
            if (!(rows[0].approveState == "2"||rows[0].approveState == "3")) {
            	if(rows[0].approveState=="1"){
            		var url = "approve.html?s=" + Math.random()+"&tempId="+rows[0].tempId;
            		$Core.UI.openDialog("approve", url,
            				{
            			title: '审核',
            			width: '30%',
            			height: '45%',
            			onClose: function () {
            				$("#dglist").datagrid("load");
            			}
            				});
            	}else{
            		$Core.UI.message.warning("请先提交数据！");
            	}
            }else {
                $Core.UI.message.warning("该条记录已审核，请选择其他记录！");
            }
        } else {
            $Core.UI.message.warning("请选择一条记录！");
        }