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<title>要素の取得と操作1～要素の指示と中身の書き換え</title>
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<h1>要素の取得と操作1～要素の指示と中身の書き換え</h1>
<div>span:<span>あああ</span></div>
<div>span:<span>あああ</span></div>
<div>span.test:<span class="test">あああ</span></div>
<div>span.test:<span class="test">あああ</span></div>
<div>span.test#a:<span class="test" id="a">あああ</span></div>
<div>span.test#b:<span class="test" id="b" >あああ</span></div>
<script>
var span_elements = document.getElementsByTagName('span');
// span_elements[0].innerHTML = 'span[0]:いいい';
var id_b = document.getElementById('b');
// id_b.innerHTML = 'span#b:いいい';
var class_tests = document.getElementsByClassName('test');
// class_tests[1].innerHTML = 'span.test[1]:いいい';
</script>
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