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.
注意:
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 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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