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<title>删除数组元素的粗略方法</title>
<script src="../unitl/test.js"></script>
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#results li.pass {color:green;}
#results li.fail {color:red;}
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<script>
const ninjas = ["Yagyu","Kuma","Hattori","Fuma"];
delete ninjas[1];
//虽然删除了元素的值，但是数组长度仍然为4。
assert(ninjas.length === 4,"Length still reports that there are 4 item");
assert(ninjas[0]==="Yagyu","First item is Yagyu");
assert(ninjas[1] === undefined,"We've simply created a hole");
assert(ninjas[2] === "Hattori","Hattori is still the third item");
assert(ninjas[3] === "Fuma","And Fuma is the last item");
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这种删除数组元素无效，只是在数组中创建了一个空元素。数组仍然有4个元素，其中我们想要删除的元素是undefined。