代码编辑器：
x
1
<p>全局变量计数</p>2
<script>3
var counter = 0;4
function add() {5
return counter += 1;6
}7
8
function myFunction(){9
document.write(add());10
}11
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myFunction();13
</script>14
<p>全局变量计数</p><script>var counter = 0;function add() { return counter += 1;}function myFunction(){ document.write(add());}myFunction();</script>