今天項目集成富文本編輯器ueditor時, 需要將圖片存儲到cdn源站,想通了流程,覺得這都小意思,一頓操作猛如虎,沒想到跑起來時出問題了,定位原因,循環裏死活取不到正確的數據, 話不多數上代碼
<?php
$data = ['a','b','c','d'];
foreach ($data as $k=>&$v){
$v.=$k ;var_dump($v);
}
// unset($v);
foreach ($data as $k=>$v){
var_dump($data);
}
打印結果:
string(2) "a0"
string(2) "b1"
string(2) "c2"
string(2) "d3"
array(4) {
[0]=>
string(2) "a0"
[1]=>
string(2) "b1"
[2]=>
string(2) "c2"
[3]=>
&string(2) "a0"
}
array(4) {
[0]=>
string(2) "a0"
[1]=>
string(2) "b1"
[2]=>
string(2) "c2"
[3]=>
&string(2) "b1"
}
array(4) {
[0]=>
string(2) "a0"
[1]=>
string(2) "b1"
[2]=>
string(2) "c2"
[3]=>
&string(2) "c2"
}
array(4) {
[0]=>
string(2) "a0"
[1]=>
string(2) "b1"
[2]=>
string(2) "c2"
[3]=>
&string(2) "c2"
}
百度一下 結果 問題就出在引用上
Reference of a $value and the last array element remain even after the foreach loop. It is recommended to destroy it by unset().
第一個循環結束後, $v引用仍然存在. 第二個循環開始, $v 每次都會被賦值.加入unset 果然輸出預期的結果了