Where are integers commonly used in programming?

Answer 1

Counts and array subscripts.
Sometimes but not too often they are also used for flags (1=yes, 0=no).

Answer 2

[lower limit] ...-5,-4,-3,-2,-1,0,1,2,3,4,5... [upper limit]

Different programming languages define integers differently. For example, you can have 16-bit integers, 32-bit integers, 64-bit integers. You can have signed or unsigned integers (those that can or cannot contain negative numbers). Each type contain a different range of numbers. For example, an int data type in C# can contain a number within the following range: -2,147,483,648 to 2,147,483,647.

There are countless integer types.

Answer 3

Counters in loops as in

for (int i=0; i<6; i++) {
do_something_with(i);
}

Answer 4

counters in loops, boolean in languages that do not have boolean, flags, accessing an array etc.