カテゴリー: JavaScript

<script> document.addEventListener('DOMContentLoaded', function(){ var start_pos = 0; window.addEventLis […]

if (typeof a === "undefined") { alert("aは未定義"); } 参考： ・undefined - JavaScript | MDN ・JavaScript：undefined値の判定: […]

■書き換え前 var url="https://example.com/script.js"; document.write('<script type="text/javascript" src="'+url+' […]

var httpObj = new XMLHttpRequest(); httpObj.open("GET", "http://example.com", true); httpObj.onreadystatechang […]

javascript: (function() { var ele = document.createElement('textarea'); ele.style.width = '100%'; ele.value = […]