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



[解决办法]
变通一下

PHP code

$ch = '';foreach($d as $v){    echo $ch . ltrim($v['a'],"Days_");    $ch = ',';}
[解决办法]
substr($str,0,-1)或者放入数组中。再用implode连接