PHP - 如何检查字符串是否包含特定文本
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PHP - How to check if a string contains a specific text
提问by Chead
<?php
$a = '';
if($a exist 'some text')
echo 'text';
?>
Suppose I have the code above, how to write the statement "if($a exist 'some text')"?
假设我有上面的代码，如何写语句“if($a exists 'some text')”？
回答by Dai
Use the strposfunction: http://php.net/manual/en/function.strpos.php
使用strpos函数：http: //php.net/manual/en/function.strpos.php
$haystack = "foo bar baz";
$needle = "bar";
if( strpos( $haystack, $needle ) !== false) {
echo "\"bar\" exists in the haystack variable";
}
In your case:
在你的情况下：
if( strpos( $a, 'some text' ) !== false ) echo 'text';
Note that my use of the !==operator (instead of != falseor == trueor even just if( strpos( ... ) ) {) is because of the "truthy"/"falsy"nature of PHP's handling of the return value of strpos.
请注意，我使用的!==运营商（而不是!= false或者== true甚至仅仅if( strpos( ... ) ) {）是因为的“truthy” /“falsy”的PHP处理的返回值的性质strpos。
回答by Blender
Empty strings are falsey, so you can just write:
空字符串是假的，所以你可以写：
if ($a) {
echo 'text';
}
Although if you're asking if a particular substring exists in that string, you can use strpos()to do that:
尽管如果您询问该字符串中是否存在特定的子字符串，您可以使用以下strpos()方法：
if (strpos($a, 'some text') !== false) {
echo 'text';
}
回答by Leeish
http://php.net/manual/en/function.strpos.phpI think you are wondiner if 'some text' exists in the string right?
http://php.net/manual/en/function.strpos.php我想如果字符串中存在“某些文本”，您会感到奇怪吗？
if(strpos( $a , 'some text' ) !== false)
回答by Havenard
You can use strpos()or stripos()to check if the string contain the given needle. It will return the position where it was found, otherwise will return FALSE.
您可以使用strpos()或stripos()检查字符串是否包含给定的针。它将返回找到它的位置，否则将返回 FALSE。
Use the operators ===or `!== to differ FALSE from 0 in PHP.
===在 PHP 中使用运算符或 `!== 来区分 FALSE 和 0。
回答by Jesse
If you need to know if a word exists in a string you can use this. As it is not clear from your question if you just want to know if the variable is a string or not. Where 'word' is the word you are searching in the string.
如果您需要知道字符串中是否存在某个单词，您可以使用它。因为从您的问题中不清楚您是否只想知道变量是否是字符串。其中“单词”是您在字符串中搜索的单词。
if (strpos($a,'word') !== false) {
echo 'true';
}
or use the is_string method. Whichs returns true or false on the given variable.
或使用 is_string 方法。对于给定的变量，whichs 返回 true 或 false。
<?php
$a = '';
is_string($a);
?>
回答by Kermit
You can use the ==comparison operatorto check if the variable is equal to the text:
您可以使用==比较运算符来检查变量是否等于文本：
if( $a == 'some text') {
...
You can also use strposfunction to return the first occurrence of a string:
您还可以使用strpos函数返回字符串的第一次出现：
<?php
$mystring = 'abc';
$findme = 'a';
$pos = strpos($mystring, $findme);
// Note our use of ===. Simply == would not work as expected
// because the position of 'a' was the 0th (first) character.
if ($pos === false) {
echo "The string '$findme' was not found in the string '$mystring'";
} else {
echo "The string '$findme' was found in the string '$mystring'";
echo " and exists at position $pos";
}
回答by P44T
Do mean to check if $a is a non-empty string? So that it contains just any text? Then the following will work.
是否意味着检查 $a 是否为非空字符串？所以它只包含任何文本？然后以下将起作用。
If $a contains a string, you can use the following:
如果 $a 包含字符串，则可以使用以下内容：
if (!empty($a)) { // Means: if not empty
...
}
If you also need to confirm that $a is actually a string, use:
如果您还需要确认 $a 实际上是一个字符串，请使用：
if (is_string($a) && !empty($a)) { // Means: if $a is a string and not empty
...
}
回答by Maneesh Mehta
you can use this code
你可以使用这个代码
$a = '';
if(!empty($a))
echo 'text';
