?????? ??
??? ?? ??? ??? ?????.
JavaScript ??
JavaScript??? ??? ??? ?????.
JavaScript?? ??? ??? ??? ??, ?? ? ??? ?????.
JavaScript ?? ??: ?? ??? ??? ?????.
JavaScript ?? ??
??? ?? ??? ???? ??? ?? ?????.
?? ??: ?? ????? ??? ? ????.
??
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>php中文網(php.cn)</title>
</head>
<body>
<p>局部變量在聲明的函數內可以訪問。</p>
<p id="demo"></p>
<script>
myFunction();
document.getElementById("demo").innerHTML =
"我可以顯示 " + typeof carName;
function myFunction()
{
var carName = "Volvo";
}
</script>
</body>
</html>????? ???? ??? ???
?? ??? ?? ???? ???? ??? ?? ?? ???? ?? ??? ??? ??? ? ????.
?? ??? ?? ??? ??? ? ????, ?? ?? ? ???? ?????.
JavaScript ?? ??
?? ???? ??? ??? ?? ?????.
?? ???? ?? ??? ????. ? ???? ?? ????? ??? ??? ? ????.
?
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>php中文網(php.cn)</title>
</head>
<body>
<p>全局變量在任何腳本和函數內均可訪問。</p>
<p id="demo"></p>
<script>
var carName = "Volvo";
myFunction();
function myFunction()
{
document.getElementById("demo").innerHTML =
"我可以顯示 " + carName;
}
</script>
</body>
</html>????? ???? ??? ???
??? ?? ??? ???? ?? ??(var ???? ???? ??) ?? ??? ?? ?????.
?? ??? carName? ?? ?? ??? ?? ?????.
?
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>php中文網(php.cn)</title>
</head>
<body>
<p>
如果你的變量沒有聲明，它將自動成為全局變量：
</p>
<p id="demo"></p>
<script>
myFunction();
document.getElementById("demo").innerHTML =
"我可以顯示 " + carName;
function myFunction()
{
carName = "Volvo";
}
</script>
</body>
</html>????? ???? ??? ???
HTML? ?? ??
HTML?? ?? ??? ? ?????. ?? ??? ??? ? ??? ????.
Example
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>php中文網(php.cn)</title>
</head>
<body>
<p>
在 HTML 中, 所有全局變量都會成為 window 變量。
</p>
<p id="demo"></p>
<script>
myFunction();
document.getElementById("demo").innerHTML =
"我可以顯示 " + window.carName;
function myFunction()
{
carName = "Volvo";
}
</script>
</body>
</html>????? ???? ??? ???
