这行 JavaScript 代码是什么 x.style.backgroundColor = x.style.backgroundColor == "yellow" ? "pink" : "yellow";"在下面编写的程序中？
<!DOCTYPE html>
<html>
<body>
<p>In this example, the setInterval() method executes the setColor() function once every 300 milliseconds, which will toggle between two background colors.</p>
<button onclick="stopColor()">Stop Toggling</button>
<script>
var myVar = setInterval(function(){ setColor() }, 300);
function setColor() {
var x = document.body;
x.style.backgroundColor = x.style.backgroundColor == "yellow" ? "pink" : "yellow";
}
function stopColor() {
clearInterval(myVar);
}
</script>
</body>
</html>
最佳答案
这是 ternary operator .
condition ? expr1 : expr2
这与:
相同if (condition) expr1;
else expr2;
所以在你的情况下:
x.style.backgroundColor = x.style.backgroundColor == "yellow" ? "pink" : "yellow"
相当于:
if (x.style.backgroundColor == "yellow")
x.style.backgroundColor = "pink";
else x.style.backgroundColor = "yellow";
关于javascript - 是什么 ？ JavaScript 以及它是如何工作的？，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/36688334/