substr_count
(PHP 4, PHP 5)
substr_count -- Count the number of substring occurrences
说明
int
substr_count ( string haystack, string needle [, int offset [, int length]] )
substr_count() returns the number of times the
needle substring occurs in the
haystack string. Please note that
needle is case sensitive.
注:
This function doesn't count overlapped substrings. See the example below!
参数
- haystack
The string to search in
- needle
The substring to search for
- offset
The offset where to start counting
- length
The maximum length after the specified offset to search for the
substring. It outputs a warning if the offset plus the length is
greater than the haystack length.
返回值
This functions returns an integer.
范例
例子 1. A substr_count() example
<?php
$text = 'This is a test';
echo strlen($text); // 14
echo substr_count($text, 'is'); // 2
// the string is reduced to 's is a test', so it prints 1
echo substr_count($text, 'is', 3);
// the text is reduced to 's i', so it prints 0
echo substr_count($text, 'is', 3, 3);
// generates a warning because 5+10 > 14
echo substr_count($text, 'is', 5, 10);
// prints only 1, because it doesn't count overlapped subtrings
$text2 = 'gcdgcdgcd';
echo substr_count($text2, 'gcdgcd');
?>
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