angular.js - ng-model如何綁定二選一的單選項方塊？

Question

Answer 1

<label>
    <input type="radio" ng-model="sex" value="male">
    <span>男</span>
</label>
<label>
    <input type="radio" ng-model="sex" value="female">
    <span>女</span>
</label>
{{sex}}

至於name屬性，我試了一下只要ng-model綁定的值一樣就認為是一組

Answer 2

用ng-checked來

<label class="">
    <input type="radio" ng-checked="option==1" ng-click="option=1">
    <span>a</span>
</label>
<label class="">
    <input type="radio" ng-checked="option==2" ng-click="option=2">
    <span>b</span>
</label>

Answer 3

單選框少了name屬性，瀏覽器怎麼知道你是一組單選框，angular怎麼知道是一組單選框？