JavaScript 控制 Radio 单选框的选中、禁用与事件监听

<div>
	<input type="radio" name="cgmd" value="学习" checked="checked"><span class="cgsySpan">学习</span>
    <input type="radio" name="cgmd" value="探亲"><span class="cgsySpan">探亲</span>
    <input type="radio" name="cgmd" value="商务"><span class="cgsySpan">商务</span>
    <input type="radio" name="cgmd" value="劳务"><span class="cgsySpan">劳务</span>
    <input type="radio" name="cgmd" value="旅行"><span class="cgsySpan">旅行</span>
    <input type="radio" name="cgmd" value="其他"><span>其他</span>
</div>

var obj = document.getElementsByName("cgmd");//获取组件
for (var i=0;i<obj.length;i++){
	//判断值
   if(obj[i].value == '学习'){
   		//设置选中
        obj[i].checked = true;
    }
}

var obj = document.getElementsByName("cgmd");//获取组件
// 设置所有不可选
for (var i=0;i<obj.length;i++){
	obj[i].disabled = true;
}

var CGMD = '探亲'
var obj = document.getElementsByName("cgmd");//获取组件
for (var i=0;i<obj.length;i++){
	//判断值
   if(obj[i].value == CGMD){
   		//设置选中
        obj[i].checked = true;
    }else{
    	//设置不可选
    	obj[i].disabled= true;
    }
}

$('input[type=radio][name=cgmd]').change(function() {
	console.log(this.value);
});