Explain about Nested Loops with Examples in C language

When we are placing a loop within the loop body, then it is called Nested loop. In implementation, when we require to repeat block of the statement, then go for loop, if complete loop body, if we required to repeat “n” no of times then go for nested loops. ?

Syntax :-

Assignment; While(condition1) { Statement 1; Statement 2; ----------------- Asignment2; While(condition2) { Statement 3; Statement 4; ………………….. ………………….. Include; } ……………………. Include; }

• When we are working with the nested loops, always execution process will starts from outerloop condition. Ie condition1
• Whenever the outerloop condition is true, then control will pass within the outerloop.
• In order to execute the outerloop, if any while statements are occur, those are called “innerloop”
• Whenever the innerloop is occur, then we required to check inner loop condition i.e, condition 2
• If the innerloop condition is true then control will pass within the innerloop and until the inner loop condition became false, complete body will be repeated “n” no. of times.
• Whenever the inner loop condition is false, then control will pass to outer loop and until the outer loop condition is false, it will be repeated “n” no. Of times
• Enter two values : 2 4

Void main() { Int i,n,n1,n2; Clrscr(); Printf(“Enter two values”); Scanf(“%d%d”,&n1,&n2);                        n1              n2 I=1;                                                               2                4 While(i<=10)                                                 n            as n=n1 {                                                                                   checkout conditions Printf(“\n”); N=n1; While(n<=n2) { Printf(“%3d%2d=%2d”,n,i,n,i); N=n+1; } I=i+1; } Getch();       Enter a value : 6 1 1 2 1 2 3 1 2 3 4 1 2 3 4 5 1 2 3 4 5 6   Enter a value : 6 6 5 4 3 2 1 5 4 3 2 1 4321 321 21 1  

1. Void main()

{ Int i,n,dn; Clrscr(); Printf(“Enter a value”); Scanf(“%d”,&n); I=n; While(i>=1) Printf(“\n”); Dn=i; While(dn>=i) { Printf(“%d”,dn) Dn=dn-1; I=i-1; } Getch(); }   o/p : 65431 54321 4321 321 21 1    

• Voidmain()

{ Int i,n,in; Clrscr(); Printf(" Enter a value”); Scanf(“%d”,&n); I=1; While(i<=0) Printf(“\n”); In=i; While(in<=n) { Printf(“%d”,in); In=in+1; } I=i+1; Getch(); }       o/p : Enter a value :6   1234356 23456 3456 456 56 6  

• Void main()

{ Int i,n,dn; Clrscr(); Printf("Enter a value:”); Scanf(“%d”, &n); I=n; While(i<=n) { Printf(“\n”); Dn=n; While(dn>=i) { Printf(“dn”,dn); Dn=dn-1; } I=i+1; } Getch(); }   o/p:-  654321 65432 6543 654 65 6  

Void main()

{ Int i,n,s,in; Clrscr(); Printf(“Enter a value”); Scanf(“%d”,&n); I=1; While(i<=n) { Printf(“\n”); S=1; While(s<=n-1) { Printf(“*”); S=s+1; } In=1; While(in<=i) { Printf(“%d”,in); In=in+1; } I=i+1; { Getch(); } o/p : enter a value : 6 ***** 1 ***** 2 ***123 ***234 ***345 123456  

• Void main()

{ Printf(“i,n,in”); Clrscr(); Printf(“enter a value”); Scanf(“%d”,&n); I=1; While(i<=n) { Printf(“\n”); In=1; While(in<=i) { Printf(“%d”,i); In=in+1; } I=i+1; } Getch(); } o/p: 1 22 333 444 5555 66666  

• Void main()

{ Int i,in,n; Clrscr(); Printf(“enter a value”); Scanf(“%d”,&n); I=1; While(i<=n) { Printf(“\n”); In=1; While(in<=i) { If(i%2==0) Printf(“*”); Else Printf(“%d”,in); In=in+1; } I=i+1; } Getch(); } o/p : 1 ** 123 **** 12345 *****    

• Void main()

{ Int i,in,n; Clrscr(); Printf(“enter a value”); Scanf(“%d”,&n); I=1; While(i<=n) { Printf(“\n”); In=1; While(in<=i) { If(i%2==0 && in%2!=0) Printf(“*”); Else if (i%2!=0 && in%2==0) Printf(“*”); Else Printf(“%d”,in); In=in+1; } I=i+1; } Getch(); } o/p: 1 *2 1*3 *2*4 1*3*5 *2*4*6  

• Void main()

{ Int i,in,n; Clrscr(); Printf(“enter a value”); Scanf(“%d”,&n); I=1; While(i<=n) { Printf(“\n”); In=1; While(in<=i) { If(in%2==0) Printf(“*”); Else Printf(“%d”,in); In=in+1; } I=i+1; } Getch(); } o/p : 1 1 * 1 * 3 1 * 3 * 5 1 * 3 * 5 *  

• Void main()

{ Int i,in,n,k; Clrscr(); Printf(“enter a value”); Scanf(“%d”,&n); I=1; K=1; While(i<=n) { Printf(“\n”); In=1; While(in<=i) { Printf(“%3d”,k); In=in+1; K=k+1; } I=i+1; }   o/p: 1 2 3 456 78910 1112131415 1617181920    

• Void main()

{ Int i,n,s,dn; Clrscr(); Printf(“Enter a value”); Scanf(“%d”,&n); I=1; While(i<=n) { Printf(“\n”); S=1; While (s<=i-1) { Printf(“*”); S=s+1; } Dn=n; While(dn>=1) { Printf(“%d”,dn); Dn=dn-1; } I=i+1; } Getch(); }   o/p: 654321 *65432 **6543 ***654 ****65 *****6  

• Void main()

{ Int i,n,s,dn,in; Clrscr(); Printf(“Enter a value”); Scanf(“%d”,&n); I=n; While(i>=1) { Printf(“%d”,in); In=in+1; } S=1; While(s<=(i-1)*2) { Printf(“*”); S=s+1; } Dn=i; While(dn<=n) { Printf(“%d”,dn); Dn=dn+1; } I=i-1; } Getch(); } o/p: 1 * * * * * * * * * * 6 1 2 * * * * * * * * 56 1 2 3 * * * * * * 4 5 6 1 2 3 4 * * * * 3 4 5 6 1 2 3 4 5 * * 2 3 4 5 6 1 2 3 4 5 6 1 2 3 4 5 6      

• Voidmain()

{ Int i,n,in,dn,s; Clrscr(); Pritntf(“Enter a value”); Scanf(“%d”,%n); I=n; While(i>=1) { Printf(“\n”); S=1; While(s<i-1) { Printf(“*”); S=s+1; } Dn=n; While(dn>=1) { Printf(“%d”,dn); Dn=dn-1; } in=i+1; While(in<=n) { Printf(“%d”,in); In=in+1; } I=i-1; } Getch(); }  

• Void main()

{ Int i,n,in,dn,s; Clrscr(); Printf(“Enter a value”); Scanf(“%d”,&n); I=1; Which(i<=n) { Printf(“\n”); S=1; While(s<=n-1) { Printf(“*n”); S=s+1; } In=1; While(in<=1) { Printf(“%d”,in); In=in+1; } Dn=i-1; While(d>=1) { Printf(“%d”,dn); Dn=dn-1; } I=i+1; } In=1; While(in<=i) { Printf(“%d”,in) In=in+1; } Dn=i-1; While(dn>=1) { Printf(“%d”,dn); Dn=dn-1; } I=i+1; I=1; While(i<=n-1) { Printf(“\n”); S=1; While(s<=i) { Printf(“*”); S=1; While(s<=i) { Printf(“*”); S=s+1; } In=1; While(in<=n-1) { Printf(“%d”,in); In=in+1; } Dn=n-i-1; While(dn>=1) { Printf(“%d”,dn) Dn=dn-1; } I=i+1; } Getch(); }