nested while loop flow chart in C language

Given Diagram is the flowchart how while loop works in c programming.
Initially, Outer while loop executes only once. outer while loop evaluates the test expression. When the condition is false, The flow of control skips the execution and control come out the outer loop.When the condition is true, the flow of control jumps to the inner while loop. Then, test expression evaluates the condition of the inner loop. if the test expression is true then the block of statements inside the inner while loop executes, If the test expression is false then skips the statement execution and control jumps out of the inner loop and start executing outer loop statement "update expression outer loop". after successful execution of the statement control goes back to while condition outer loop and test the condtion.The process continues till condition is true.

nested while loop syntax C Programming language.

Syntax of Nested while loop in C:

Let us study real-world syntax of Nested while loop and then we will look detail into all parts of the Nested while loop.

/* statements outside loop.
initilization */
  while(Outer Condition)
  {
     /*Outer while statements */
     while(Inner Condition)
     {
      /*Inner while Statements; */
     }
     /*Outer While Statements */
  }
/* statement outside loop */

Syntax Explanation :
all statements ouside the loops executes i.e /*Statements outside loop */
1. Control enters into the outer while loop.
2.The control jumps to the Outer Condition inside outer while loop.
3. The condition is tested. Here condition tested either be true or false.
  3.a. if the condition tested is false, then control do not enters in to loops. it transfer to outside loop and start executing /* Statements outside the loop.*/
and program stops.
 3.b. if the condition tested is true, then the flow goes inside the loop and executes the statements /* Outer while statements. */
4.after executing these statements control enters inner while loop.
Then The inner condition tested inside inner while loop.
5.a if tested condition is true then statements inside inner while loop i.e/* Inner while statements */ executes .
6.after this control jumps back to test inner condition. that means execution repeats from step no 4.
5.b if tested condition is false control jumps outside the inner while loop and execute /*Outer while statements.*/ control jumps to step 7.
7.Control jumps back to outer while loop again AND test the outer condition.
In short we can say it again repeat continuation from step no 2.

C program to illustrate use of Nested while loop

/* C program given below displays Table from 1 to 10 Number */
#include <stdio.h>
int main()
 {
  int n=1,i=1;
  printf("\n Table from 1...10 Using Nested While loop");
  while(n<=10)
   {
   i=1;
   while(i<=10)
    {
     printf("\t %d",n*i);
     i++;
    }
   n++;
   printf("\n");
   }
  return(0);
 }

Output:

Table from 1...10 Using Nested While loop


1 2    3   4   5    6   7   8  9   10
2  4   6   8   10  12  14  16  18  20
3  6    9   12  15  18  21  24  27  30
4  8   12  16  20  26  28  32  36  40
5  10   15  20  25  30  35  40  45  50
6  12   18  24  30  36  42  48  54  60
7  14   21  28  35  42  49  56  63  70
8  16   24  32  40  48  56  64  72  80
9  18   27  36  45  54  63  72  81  90
10 20   30  40  50  60  70  80  90  100

Explanation : Variable int n=1,i=1; declared and initilized
printf("\n Table from 1...10 Using Nested While loop");
Shows the message on console
Table from 1...10 Using Nested While loop
Next control enters into the outer while(n<=10) loop and test the condition
i.e. while (1<10) which is true control enters into the body of outer loop .
after that i=1 is initilized, next control enters into the inner loop and test the condition while(i<=10)
which is true and control enters into the inner loop body
and executes printf("\t %d",n*i); displays output 1 .
Next i++ increase value of i by 1 then i becomes i=2 .
The control enters into the inner while loop and test the condition while(i<=10) which is true and execute body of loop and shows output 2.
The inner loop continues till value of i <= 10 i.e. while(i<=10).
If while(i<=10 ) becomes false control goes to outer loop and increase the value of n++ by one.
then n becomes n=2 and the rest of loop iteration continues till value of n<=10.
finaly we get the table output from 1 2 3........10.