Question

以下代码中的哪个错误会导致if（is1Pressed = true）控制台在控制台中重复记录“1”

 if(is1Pressed = true){
    console.log("1");
    p.innerHTML = "<audio autoplay='autoplay' src='button1.wav'/>";
  }
  else if(is2Pressed = true) {
        console.log=("2");
    p.innerHTML = "<audio autoplay='autoplay' src='button1.wav'/>";
  }
else if(is3Pressed = true) {
 p.innerHTML = "<audio autoplay='autoplay' src='button1.wav'/>";
}
else if(is4Pressed = true) {
 p.innerHTML = "<audio autoplay='autoplay' src='button1.wav'/>";
}
else if(is5Pressed = true) {
 p.innerHTML = "<audio autoplay='autoplay' src='button1.wav'/>";
}
else 
{
  p.innerHTML = "<audio autoplay='autoplay' src='button1.wav'/>";
}

Answer 1

您使用的是=，即分配运算符，而不是==或===。也就是说，您可以针对true明确停止检查，只需检查变量的真实性，即可获得更简洁的代码：

if (is1Pressed) {
    console.log("1");
    p.innerHTML = "<audio autoplay='autoplay' src='button1.wav'/>";
}
else if (is2Pressed) {
    console.log = ("2");
    p.innerHTML = "<audio autoplay='autoplay' src='button1.wav'/>";
}
else if (is3Pressed) {
    p.innerHTML = "<audio autoplay='autoplay' src='button1.wav'/>";
}
else if (is4Pressed) {
    p.innerHTML = "<audio autoplay='autoplay' src='button1.wav'/>";
}
else if (is5Pressed) {
    p.innerHTML = "<audio autoplay='autoplay' src='button1.wav'/>";
}
else {
    p.innerHTML = "<audio autoplay='autoplay' src='button1.wav'/>";
}

Answer 2

我想你想要is1Pressed == true。否则你说is1Pressed等于true而不是检查它是否等于它。

Answer 3

=是赋值运算符，而不是比较。通常，对于比较，您应该使用===但是因为您尝试与true进行比较，所以根本不需要任何比较（我假设is1Pressed是布尔值）：

if(is1Pressed = true){

应该是：

if(is1Pressed){

同样适用于所有其他if语句。

Answer 4

你必须使用＆＃34; ==＆＃34;而不是＆＃34; =＆＃34;检查条件

if(is1Pressed == true){
    console.log("1");
    p.innerHTML = "<audio autoplay='autoplay' src='button1.wav'/>";
  }
  else if(is2Pressed == true) {
        console.log=("2");
    p.innerHTML = "<audio autoplay='autoplay' src='button1.wav'/>";
  }
else if(is3Pressed == true) {
 p.innerHTML = "<audio autoplay='autoplay' src='button1.wav'/>";
}
else if(is4Pressed == true) {
 p.innerHTML = "<audio autoplay='autoplay' src='button1.wav'/>";
}
else if(is5Pressed == true) {
 p.innerHTML = "<audio autoplay='autoplay' src='button1.wav'/>";
}
else 
{
  p.innerHTML = "<audio autoplay='autoplay' src='button1.wav'/>";
}

JavaScript如果声明

4 个答案: