1. Get the string: substr($str, $start, $length)
<? php $email = '[email protected]' ; echo 'original string: '. $email ; echo '<hr>' ; // Starting from 0, get 7 characters echo substr ( $email , 0,7); echo '<hr>' ; // -3: Negative numbers count from the end echo substr ( $email ,-3,3); echo '<hr>' ; ?>
2, the replacement string: substr_replace()
<? php $email = '[email protected]' ; echo 'original string: '. $email ; echo '<hr>' ; // Note that negative numbers are different from positive numbers, negative numbers start from -1, Positive numbers start from 0 echo substr_replace ( $email ,'163',9,2); echo '<hr>' ; echo substr_replace ( $email ,'cn',-3,3); echo '<hr>' ; // Set the string length to 0 to achieve insertion without deletion echo substr_replace ( $email ,'_zhu',8,0); echo '<hr>' ; // Set an empty string to achieve insertion deletion echo substr_replace ( $email , '', 0,4); echo '<hr>' ; // insert characters at the beginning echo substr_replace ( $email , 'My mailbox:', 0,0); echo '< hr>' ; ?>
3, substr_count(): the frequency (number of times) of the query string
<?php $email = 'My blog name is cl94,welcome to my blog'; echo '原始字符串：'.$email; echo '<hr>'; echo substr_count($email,'blog',0,10); echo '<hr>'; ?>
4, substr_compare($str, $str1, startpos ): compare strings
<? php $str1 = 'My blog name is cl94,welcome to my blog' ; $str2 = 'My blog' ; // startpos: specifies where in string1 to start the comparison. If negative, count from the end of the string. //Return result (0: equal; <0:$str1<$str2; >0:$str1>$str2); //Compare the ascii value echo substr_compare ( $str1 , $str2 ,0); echo '<hr>' ; echo substr_compare($str1, $str2,0,7);echo '<hr>'; ?>
