string_replace 替换循环中的第一个片段

Question

这个问题是基于我之前的问题。这是我的代码。

$this->logger->debug($datauser);   // [ZN1961] => Array([#A] => 12 >  4 [#B] => 12 >  2 ), [ZN1962] => Array ([#A] => 20 >  4 [#B] => 20  >  2 )
logicexpression = ((#A) OR (#B) );

$newArr = array();
foreach ($datauser as $key => $value) {
    foreach ($value as $logname => $cond) {
        $this->logger->debug($cond);     /// WHEN DEBEG HERE it gives correctly the $cond in each iteration          
        $logicexpression =str_replace($logname, $cond, $logicexpression);
    }
$this->logger->debug($logicexpression ); // here I am always getting (12 >  4) OR (12 >  2)
    }
`

所以我的问题就像我在代码中提到的那样，我总是得到 (12 > 4) OR (12 > 2)。
所以输出是，

@547,12 >  4
@547, 12 >  2
@557, (12 >  4) OR (12 >  2)
@547, 20 >  4
@547, 20 >  2
@557, (12 >  4) OR (12 >  2) // here it should has to come as (20 >  4) OR (20 >  2)`

即使我得到 $cond 正确，但调试无法在迭代中替换相关的 $cond。我不明白为什么？请帮我。

Answer 1

您必须在迭代中定义一个新变量 $newlogicexpression，否则在第一次迭代后您在 $logicexpression 中不再有 (#A) OR (#B) 并且替换将不起作用...

$logicexpression = ((#A) OR (#B) );
foreach ($datauser as $key => $value) {
    $newlogicexpression = $logicexpression;
    foreach ($value as $logname => $cond) {
        $newlogicexpression = str_replace($logname, $cond, $newlogicexpression);
    }
    $this->logger->debug($newlogicexpression);
}

string_replace 替换循环中的第一个片段

string_replace replacing very first segment in loop

php

iteration

str-replace