PHP删除指定字符。该如何解决 _PHP

PHP删除指定字符。

PHP code


$d = array(
  0 => array(
    'a' => string 'Days_3' (length=6)
    'b' => string '3 Days' (length=6)
  )
  1 => array(
    'a' => string 'Days_7' (length=6)
    'b' => string '7 Days' (length=6)
  )
  2 => array(
    'a' => string 'Days_14' (length=7)
    'b' => string '14 Days' (length=7)
  )
  3 => array(
    'a' => string 'Days_30' (length=7)
    'b' => string '30 Days' (length=7)
  )
  4 => array(
    'a' => string 'Days_60' (length=7)
    'b' => string '60 Days' (length=7)
  ));
foreach($d as $v)
{
    echo ltrim($v['a'],"Days_").",";
}

输出的 3,7,14,3,60, ,现在用什么方法能把最后一个","去掉，结果：3,7,14,3,60

------解决方案--------------------
变通一下

PHP code

$ch = '';
foreach($d as $v)
{
    echo $ch . ltrim($v['a'],"Days_");
    $ch = ',';
}

------解决方案--------------------
substr($str,0,-1)或者放入数组中。再用implode连接