How to format a control like a variable?

Thanks for your answer but it is not asked. I mean that you touch control as variable such as you have textbox which their names are textbox1,textbox2,textbox3 etc. So, I want these controls use in a loop but I wrote just once. for( i=1 ; i<= 3 ;i++) { textbox{i};//{} => this brace not braket like this =>[] }