if语句的getElementsByClassName问题

Question

有人能帮忙吗？我似乎无法弄清楚为什么它不起作用。谢谢。

<p class="largetext">GGS</p>

        <script type="text/javascript">

            window.addEventListener("scroll", function(){

                var textY = document.getElementsByClassName("largetext")

                for(var i = 0; i < textY.length; i++){if (2 > 1)

                    {textY[i].innerHTML = "passed"; }                                                  

                    else {

                    textY[i].innerHTML = "failed";}}) 

            </script>

Answer 1

window.addEventListener("scroll", function(){应该关闭});而不是关闭}。这是您的代码：window.addEventListener("scroll", function(){&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; var textY = document.getElementsByClassName("largetext");&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; for(var i = 0; i < textY.length; i++){&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;if (2 > 1) {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; textY[i].innerHTML = "passed";&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;} else {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; textY[i].innerHTML = "failed";&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;}&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; }&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; });.largetext {&nbsp; width: 100%;&nbsp; height: 100px;}<div class="largetext"></div><div class="largetext"></div><div class="largetext"></div><div class="largetext"></div><div class="largetext"></div><div class="largetext"></div><div class="largetext"></div><div class="largetext"></div><div class="largetext"></div><div class="largetext"></div><div class="largetext"></div><div class="largetext"></div><div class="largetext"></div><div class="largetext"></div><div class="largetext"></div>

Answer 2

问题出在您的代码中，您错过了关闭函数的花括号，这就是它抛出错误的原因。.largetext{min-height: 200vh}<p class="largetext">GGS</p>&nbsp; &nbsp; &nbsp; &nbsp; <script type="text/javascript">&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; window.addEventListener("scroll", function(){&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; var textY = document.getElementsByClassName("largetext")&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; for(var i = 0; i < textY.length; i++){&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; if (2 > 1){&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; textY[i].innerHTML = "passed";&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; }&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&nbsp;&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; else {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; textY[i].innerHTML = "failed";&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; }&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;}&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;})&nbsp;&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; </script>