


PHP gets the first non-repeating character in the character stream
This article mainly introduces the method of PHP to obtain the first non-repeating character in the character stream, involving PHP's operation skills related to traversing and judging index arrays. Friends in need can refer to it. I hope it can help everyone.
Please implement a function to find the first character that appears only once in the character stream. For example, when reading only the first two characters "go" from the character stream, the first character that appears only once is "g". When the first six characters "google" are read from this character stream, the first character that appears only once is "l".
Output description:
If there is no character that appears once in the current character stream, return # characters
Solution
Use index Array
Implementation code
<?php global $result; //Init module if you need function Init(){ global $result; $result = []; } //Insert one char from stringstream function Insert($ch) { global $result; // write code here if(isset($result[$ch])){ $result[$ch]++; }else{ $result[$ch] =1; } } //return the first appearence once char in current stringstream function FirstAppearingOnce() { global $result; foreach($result as $k =>$v){ if($v ==1){ return $k; } } return "#"; }
Related recommendations:
Related Summary of examples of using character streams in java
Detailed introduction to the difference between character streams and byte streams in Java
About character stream buffers in Java Detailed explanation of examples
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