itoa() means turn iteger to ASCII string. the reverse is atoi(). some similiar functions are hextoa()/atohex(), octtoa()/atooct(), bintoa()/atobin(), realtoa()/atoreal()...
uvm_event e_debug[NUM];
uvm_event_pool tb_pool;
string num1;
genvar i;
generate
for(i=0; i<NUM; i++)begin
iniital begin
if(i==0) tb_pool = uvm_event_pool::get_global_pool();
num1.itoa(i);
e_debug[i] = tb_pool.get({“e_debug_”,num1});
end
end