​x
 
<!DOCTYPE html>
<html>
<body>
​
<h1>JavaScript 运算符</h1>
​
<h2>一元减号</h2>
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<p id="demo"></p>
​
<script>
let x = 5;
document.getElementById("demo").innerHTML = -x;
</script>
​
</body>
</html>
​