Function "Lines(IT)" can pass value to internal table?

Hi,

i wonder is it possible to pass value back to its internal table after using function lines?

All i know is that after using using lines, you have to pass value to integer variable.

The codes below is the example that my senior use to pass value back to its own:

g_kfgr_cnt     = LINES( g_kfgr_cnt ).

g_kfgr_act_cnt = g_kfgr_cnt.
g_kfgr_cnt     = g_kfgr_cnt + 1.

I do not know which exact table my senior used, but its purpose is to count the number of key figure.