Digital logic gates

What you are talking about are not gates. The hardware doesn't work that way. Look up the instruction set for your processor and you will realise that most processors are only able to do a limited number of conditional things - i.e. test for equality, branch if equal or not equal, etc. There is no such thing as an IF gate or even a WHEN gate.

The programming loop structures of if, while, do, for and more are all high-level programming level abstractions. Instead of expecting the computer to think like you do - you should instead change your thinking to match what the computer (or your choice of programming language) can do.

Say in C, if you want to iterate from 1 to 3, you could do something like this:

int i = 0;

while (i < 3) {

  printf("Hello");

  i++;

}

or you could be nice and use a for loop:

for (int i = 0;i<3;i++) {

  printf("Hello");

}

These are all functionally the same and checks the condition at the beginning of the loop.

You can check the condition at the end of the loop - the most silly way would be to use an infinite loop, but break it if i is equal to 3:

int i = 0;

while (1) {

  printf("Hello");

  i++;

  if (i==3) {

    break;

  }

}

or you could use a do, while construct like

int i = 0;

do {

  printf("Hello");

  i++;

} while (i<2);

But be careful, as changing the checking location may change the condition required. But style wise, these are considered "ugly" most of the time, as they are difficult to understand at a glance, especially reading from top to bottom. As to what code is generated, this depends on the compiler and optimisations, so the results may be very similar in terms of actual machine code.

- Gough

Gough Lui No, it's not really the program code that is doing the heavy lifting here. All CPUs have what is known as the instruction set which is in machine code. This controls the gates etc, via microcode whitch is  a very wide word 100bits or more. Now with all that said now you need an assembler, this is where the form comes from. Next is roll your own language, where C is mostly the easiest to code. So starting a the top you must define your keywords( if, do, while, case, switch #define and so forth), you also have to define your standard symbols( <>, {}, [], (), =, ==, +, -, /, *, ++, --, ;  and others) at this point we are not talking about any IO as it is handled in a standard library that is written after the body code is finished and working. after you have your keywords done and working then you need to define a function, no not what it's named but how does it look to the code for instance for a function you need to understand what your input is.   the notation that you would use is called Bacus Nour Form mind you I have written the three below in my shorthand notation.

function: