HTML DOM Pilih panjang properti
Definisi dan Penggunaan
Properti panjang mengembalikan jumlah daftar drop-down pilihan.
tatabahasa
selectObject.length=number
Dukungan Browser
Semua browser utama mendukung properti panjang
contoh
contoh
Menampilkan jumlah daftar drop-down pilihan:
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>本教程(w3big.com)</title>
<script>
function displayResult(){
alert(document.getElementById("mySelect").length);
}
</script>
</head>
<body>
<form>
<select id="mySelect">
<option>Apple</option>
<option>Pear</option>
<option>Banana</option>
<option>Orange</option>
</select>
</form>
<button type="button" onclick="displayResult()">下拉列表中有多少选项?</button>
</body>
</html>
<html>
<head>
<meta charset="utf-8">
<title>本教程(w3big.com)</title>
<script>
function displayResult(){
alert(document.getElementById("mySelect").length);
}
</script>
</head>
<body>
<form>
<select id="mySelect">
<option>Apple</option>
<option>Pear</option>
<option>Banana</option>
<option>Orange</option>
</select>
</form>
<button type="button" onclick="displayResult()">下拉列表中有多少选项?</button>
</body>
</html>
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Pilih Objek