anIdiotsGuideToProgtest_cycles.c

#include <stdio.h>

void forExample() {
  int a=5;
  printf("--------------------------------------------------------------------------------\n");
  printf("forExample:\n");
  printf("--------------------------------------------------------------------------------\n");

  /*
  *  for(1;2;3){4}
  * 1:   something that happens at the absolute start
  * 2:   condition
  * 3:   something that happens at the end of every cycle
  * 4:   something that happens every cycle (block of code)
  */

  // at the start we create variable with type "int" named "i"
  // and we initialize (set starting value of) the variable to the value 0
  for (int i=0;i<10;i++) {
    // before every cycle starts we check the condition
    // if the condition is true (anything else than 0) we continue to the following block of code
    // if the condition is false (0) we jump out from the for cycle

    // the actual code in the block of code
    printf("%d",i);// we print the current value of "i"

    // at the end of the block we do the last part of the for statement
    // that is "i++" this adds one to the "i" variable
    // after that the condition is checked once again
  } // end of the for
  // the "i" variable doesn't exist anymore
  // here we move once the condition in for is not satisfied (is false)

  // here is another a little more cmplex example:
  // we copy the value of "a" to the newly made "i" variable
  for(int i=a;i<10;i++) {
    //we print the value of "i" and "a" in every cycle
    printf("value of i: %d; value of a: %d\n", i, a);
  }
  // here we print only the value of "a" to show its unchanged
  // "i" does not exist anymore since we are outside of the block it was declared in
  printf("value of a: %d\n", a);
  printf("--------------------------------------------------------------------------------\n");
  printf("end of for example\n");
  printf("--------------------------------------------------------------------------------\n");
}

void whileExample() {
  printf("--------------------------------------------------------------------------------\n");
  printf("whileExample:\n");
  printf("--------------------------------------------------------------------------------\n");
  // "while" is similar to "for" but is a little less complex
  // while(condition) { block of code }

  // we have to declare and initialie the "i" variable beforehand so we can use it in the while loop later
  int i=0;

  // here is the while loop itself
  while(i<10) { // start of the block
    // before we start the code here we have to check the condition
    // if the condition is true (not 0) we continue with the code inside this block
    // if the condition is false (0) we jump behind the end of this block

    //actual code in this block of code
    printf("%d\n",i);// we print the current value of "i"

    // this while cycle would be infinite without anything that is able to change the condition
    // in this case simple "i++" is enough
    // this means that we will print out values from 0 to 9 included
    i++;

    // we reached end of block
    // this means that we have to check the condition and decide if we want to continue
  } //end of the block
  printf("--------------------------------------------------------------------------------\n");
  printf("end of whileExample\n");
  printf("--------------------------------------------------------------------------------\n");

}

int main() {
  forExample();
  whileExample();

  return 0;
}