[英]how to activated new function after button clicked for three times
我想在單擊按鈕 3 次后添加新的 function 並擦除/刪除以前的 function
html 文件:
<body>
<div id="background">
<p>this background white, before</p>
</div>
<button class="btn-1">change color</button>
</body>
javascript:
const btn1 = document.querySelector(".btn-1") ;
const bg = document.getElementById("background")
const toRed = ()=>{
bg.style.backgroundColor = "red";
}
const toBlue = ()=>{
bg.style.backgroundColor = "steelblue";
}
btn1.addEventListener('click', toRed);
// 我希望這個btn1有 function 來清除 function toRed並在點擊 3 次后添加toBlue
刪除事件偵聽器並在單擊 3 次時添加一個新偵聽器:
const btn1 = document.querySelector(".btn-1"); const bg = document.getElementById("background"); var redClicked = 0; const toRed = ()=>{ bg.style.backgroundColor = "red"; redClicked++; if (redClicked >= 3) { btn1.removeEventListener('click', toRed); btn1.addEventListener('click', toBlue); } } const toBlue = ()=>{ bg.style.backgroundColor = "steelblue"; } btn1.addEventListener('click', toRed);
<body> <div id="background"> <p>this background white, before</p> </div> <button class="btn-1">change color</button> </body>
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