[hkkelvin1995]

new Float:ori[3];
GetClientAbsOrigin(client,ori);

I know it is for saving some location data
for example ori[0] is axis x , ori[1] is for y and ori[2] is for axis z
then what's about [3]?

[Powerlord]

There is no [3].

new Float:ori[3] means it's an array with 3 items numbered 0, 1, and 2.