二维数组依据键值相加

二维数组根据键值相加
怎样根据每一个数组的键值相加？


Array
(
[0] => Array
(
[reg] => 0
[regs] => 0
[login] => 7
[pay] => 0
[buy] => 4
[payment] => 11334.00
[recharge] => 1
[rechargea] => 3600.00
)

[1] => Array
(
[reg] => 1
[regs] => 0
[login] => 22
[pay] => 0
[buy] => 0
[payment] => 0.00
[recharge] => 0
[rechargea] => 0.00
)

[2] => Array
(
[reg] => 0
[regs] => 0
[login] => 5
[pay] => 0
[buy] => 1
[payment] => 376.00
[recharge] => 0
[rechargea] => 0.00
)