Why isn't this standalone code working:

為什么這個獨立代碼不起作用：

$link = 'https://google.com';

$unacceptables = array('https:','.doc','.pdf', '.jpg', '.jpeg', '.gif', '.bmp', '.png');

foreach ($unacceptables as $unacceptable)

{

if (strpos($link, $unacceptable) === true) {

echo 'Unacceptable Found
';

}

else {

echo 'Acceptable!
';

}

}

It's printing acceptable every time even though https is contained within the $link variable.

即使https包含在$ link變量中，每次打印都是可接受的。

6 个解决方案

#1

53

When in doubt, read the docs:

如有疑問，請閱讀文檔：

[strpos] Returns the numeric position of the first occurrence of needle in the haystack string.

[strpos]返回haystack字符串中第一次出現needle的數字位置。

So you want to try something more like:

所以你想嘗試更像的東西：

// ...

if (strpos($link, $unacceptable) !== false) {

Because otherwise strpos is returning a number, and you're looking for a boolean true.

因為否則strpos返回一個數字，你正在尋找一個布爾值true。

#2

7

strpos() does not return true when it finds a match, it returns the position of the first matching string. Watchout, if the match is a the beginning of the string it will return an index of zero which will compare as equal to false unless you use the === operator.

strpos()在找到匹配項時不返回true，它返回第一個匹配字符串的位置。注意，如果匹配是字符串的開頭，它將返回零索引，除非你使用===運算符，否則它將等於false。

#3

5

Your failure condition is wrong.

你的失敗情況是錯誤的。

strpos returns false if match is not found, so you need to explicitly check

如果未找到匹配，則strpos返回false，因此您需要顯式檢查

if (strpos($link, $unacceptable) !== false) {

#4

1

Strpos always return position like you search "httpsL" in your string('https://google.com';) then it return 0th position and PHP evaluate it as false.

Strpos始終返回位置，就像您在字符串中搜索“httpsL”('https://google.com';;)然后返回第0個位置，PHP將其評估為false。

please see this link:(Hope its very usefull for you): http://php.net/manual/en/function.strpos.php

請看這個鏈接:(希望它對你非常有用)：http：//php.net/manual/en/function.strpos.php

#5

0

if (strpos($link, $unacceptable))

{

} else {

/* What you want to do when it is false */

}

#6

0

strpos

strpos

function may return Boolean FALSE, but may also return a non-Boolean value which evaluates to FALSE.

function可以返回布爾值FALSE，但也可以返回一個非布爾值，其值為FALSE。

So I did like this

所以我確實喜歡這個

if (strpos($link, $unacceptable) !== false) {

//Code

}