尝试用相同的搜索字符替换部分字符串开头

Question

我正在尝试替换部分字符串。但是当我的搜索字符串以相同字符开头时我遇到了问题：

$string = "Good one :y. Keep going :y2"; 

$str = str_replace(array_keys($my_array), array_values($my_array), $string);   
$my_array= array(":y" => "a", ":y2" => "b");

输出：

Good one a. Keep going a2

我需要 str_replace() 来匹配单词 correctly/exactly。

Answer 1

尝试先替换 :y2，然后再替换 :y

$string = "Good one :y. Keep going :y2"; 

$my_array= array(":y2" => "b", ":y" => "a");

$str = str_replace(array_keys($my_array), array_values($my_array), $string);

产出

Good one a. Keep going b

Try it

Answer 2

:y\b

使用此仅替换 :y 而不是 :y2。参见演示。

https://regex101.com/r/sJ9gM7/9

$re = "":y\b"m";
$str = "Good one :y. Keep going :y2\n";
$subst = "a";


$result = preg_replace($re, $subst, $str);

与 :y2 类似，使用 :y2\b。

Answer 3

此外，您应该在使用数组之前先定义它，这应该对您有用：

$str = strtr($string, $my_array);

你的问题是 str_replace() 遍历整个字符串并替换它能替换的所有内容，你也可以在手册中看到这一点。

引自那里：

Because str_replace() replaces left to right, it might replace a previously inserted value when doing multiple replacements. See also the examples in this document.

所以为此我在这里使用了 strtr()，因为它首先尝试匹配搜索中最长的字节。

您还可以在手册中阅读此内容并从那里引用：

If given two arguments, the second should be an array in the form array('from' => 'to', ...). The return value is a string where all the occurrences of the array keys have been replaced by the corresponding values. The longest keys will be tried first. Once a substring has been replaced, its new value will not be searched again.

尝试用相同的搜索字符替换部分字符串开头

Trying to replace parts of string start with same search chars

php

regex

str-replace