两个循环foreach和未设置

Question

<?php

$array = array(a,s,d,f,g,h,j,k,l);

foreach($array as $i => &$a){
 foreach($array as $k => &$b){
    if($k = 4){
     unset($array[1]);
    }
 }

 echo $a . "
";
}

print_r($array);

CODEPAD: http://codepad.org/UoWhrIkv

Why in this example echo show me only "a" and print_r show all good? Is possible to make good showing in loop with echo?

Answer 1

Two problems here:

The first is you're using = instead of == in this line:

if($k = 4){

The second is your logic, as when your inner loop iterates over the same array, it will repeatedly unset $array[1].

That does not influence the inner foreach, but the outer one. So echo $a; has a chance to print once only.

Changing your if statement to:

if($k == 4){
  unset( $b);
}

Made the echo $a print the entire array (assuming that's what you're going for).