php - array中添加元素？

Question

$age=array("609"=>"1","610"=>"2","611"=>"3");

想达到两个结果：
1、$age=array("609"=>"1,5,7","610"=>"2","611"=>"3");

2、$age=array("609"=>"1","610"=>"2","611"=>"3","612"=>"4");

   用array_push不行；

Answer 1

1

$age['609']='1,5,7';

2

$age['612']='4';

Answer 2

第一个替换，第二个$age["612"] = "4";

Answer 3

写两个自定义的push函数就可以了