我想知道在执行代码块时是否可以在Javascript switch语句中使用类似'this'的东西。
例如:
switch(x) {
case 'The pyramids of Giza':
console.log(this);
break;
case 'The Leaning Tower of Pisa':
console.log(this);
break;
default:
console.log('Not found');
}
与:
相同switch(x) {
case 'The pyramids of Giza':
console.log('The pyramids of Giza');
break;
case 'The Leaning Tower of Pisa':
console.log('The Leaning Tower of Pisa');
break;
default:
console.log('Not found');
}
这纯粹是出于提高效率的目的,谢谢!
答案 0 :(得分:4)
您可以访问$('.nav-tabss').on('click','a',function(){
var branding = $(this).text();
if ( branding === "Branding" )
{
$('.branding').show();
$('.adverise').hide();
$('.print').hide()
}
语句中正在测试的变量;毕竟,如果switch
等于“吉萨金字塔”,则x
也必须是您希望在x
内使用的值。
case
答案 1 :(得分:2)
当您访问$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, $source);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
// if https
curl_setopt($ch, CURLOPT_SSLVERSION, 3);
// or set this option
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
$data = curl_exec($ch);
$error = curl_error($ch);
$file = $data = curl_exec($ch);
curl_close($ch);
if (file_exists($file)) {
header("Content-Type: audio/mpeg, audio/x-mpeg, audio/x-mpeg-3, audio/mpeg3");
header('Content-Disposition: attachment; filename="sometrack.mp3"');
header("Content-Transfer-Encoding: binary");
header('Content-length: ' . filesize($file));
header('X-Pad: avoid browser bug');
header('Cache-Control: no-cache');
readfile($file);
} else {
echo "no file";
}
时,case:
中指定的值的值始终是放在case:
语句中的变量。这是因为只有当变量等于switch
中指定的值时才会访问case:
,因此您知道如果您访问过该情况,那么变量的值必须与case:
中指定的值相同。因此,这是您正在寻找的代码:
case:
答案 2 :(得分:1)
//Create some users
var user1 = {name: 'modulus admin', age: 42, roles: ['admin', 'moderator', 'user']};
var user2 = {name: 'modulus user', age: 22, roles: ['user']};
var user3 = {name: 'modulus super admin', age: 92, roles: ['super-admin', 'admin', 'moderator', 'user']};
// Insert some users
collection.insert([user1, user2, user3], function (err, result) {
if (err) {
console.log(err);
} else {
console.log('Inserted %d documents into the "users" collection. The documents inserted with "_id" are:', result.length, result);
}
//Close connection
db.close();
});
应该做的伎俩