如果字符串以“xx”开头（PHP）

if string begins with "xx" (PHP)

提问by Riki137

if ($_POST['id'] beginsWith "gm") {
$_SESSION['game']=="gmod"
}
if ($_POST['id'] beginsWith "tf2") {
$_SESSION['game']=="tf2"
}

How to do this so it will work?

如何做到这一点，所以它会起作用？

采纳答案by Rocket Hazmat

if (strpos($_POST['id'], "gm") === 0) {
  $_SESSION['game'] ="gmod"
}
if (strpos($_POST['id'],"tf2") === 0) {
  $_SESSION['game'] ="tf2"
}

回答by Matt

You could use substring

你可以使用子字符串

if(substr($POST['id'],0,3) == 'tf2')
 {
  //Do something
 }

Edit: fixed incorrect function name (substring()used, should be substr())

编辑：修复了不正确的函数名称（substring()使用过，应该是substr()）

回答by Jon

You can write a begins_withusing strpos:

你可以写一个begins_withusing strpos：

function begins_with($haystack, $needle) {
    return strpos($haystack, $needle) === 0;
}


if (begins_with($_POST['id'], "gm")) {
    $_SESSION['game']=="gmod"
}

// etc

回答by Toto

NOT the fastest way to do it but you can use regex

不是最快的方法，但您可以使用正则表达式

if (preg_match("/^gm/", $_POST['id'])) {
    $_SESSION['game']=="gmod"
}
if (preg_match("/^tf2/, $_POST['id'])) {
    $_SESSION['game']=="tf2"
}

回答by PeeHaa

function startswith($haystack, $needle){ 
    return strpos($haystack, $needle) === 0;
}

if (startswith($_POST['id'], 'gm')) {
    $_SESSION['game'] = 'gmod';
}
if (startswith($_POST['id'], 'tf2')) {
    $_SESSION['game'] = 'tf2';
}

Note that when assigning values to variable use a single =

请注意，在为变量赋值时使用单个 =