The document discusses functions in the C programming language, including their definitions, declarations, and types. It provides examples of function implementations, outputs, and explores concepts like recursion and argument passing. Additionally, it touches on the differences between recursion and iteration in programming.

1. Presented By:- RUPENDRA CHOUDHARY B.Tech.- 2 nd YEAR (CSE) E.C.B. ,BIKANER FUNCTION IN ‘C’

2. A function is a block of code that perform special task of some kind. WHAT IS FUNCTION?

3. WHY WE USE FUNCTION? main() { int i; printf(“computer science \n”); for(i=0;i<20;i++) { printf(“*”); } printf(“\n engineering hobby \n”); for(i=0;i<10;i++) { printf(“#”); } }

4. C:\function.c void function(int x,char y) { int i; for(i=0;i<x;i++) { printf(“%c”,y); } }

5. #include<c:\function.c> void main() { int i; printf(“computer science’s runner \n”); function(20,’*’); printf(“engineering is hobby \n”); function(10,’#’); }

6. PARTS OF FUNCTION 1)-Declaration 2)-Calling 3)-Definition

7. DESCRIPTION int sum(int,int); void main() { int a,b,add; scanf(“%d%d”,&a,&b); add=sum(a,b); printf(“add is %d”,add); } int sum(int x,int y) { return x+y; }

8. FUNCTION TYPES 1)-No argument & No return value 2)-No argument & Having return value 3)-Having argument & No return value 4)-Having argument & Return value 5)-Recursive function

9. ILLUSTRATIONS 1)-What will be output? void main() { int i=3,r; r=sizeof f(++i)+f(--i)+f(i-2); printf(“%d%d”,r,i); } int f(int j) { if(!!j) return ++j; else return --j; }

10. 2)-What will be output? main() { int a=5,b; { int b=10; ++b; ++a; printf(“%d%d\n”,a,b); { int a=20; ++a; a=++b; printf(“%d%d\n”,a,b); } ++a; ++b; Printf(“%d%d\n”,a,b); } Printf(“%d%d\n”,a,b); }

11. 3)-What will be output ? func(int i) { if(i%2) return 0; else return 1; } main() { int i=1; i=func(i); i=func(i); printf(“%d”,i); }

12. 4)- What will be output? int max(int x,int y) { return x>y?x:y; } void main() { int m; m=max(max(4,max(11,6)),max(10,5)); printf(“%d”,m); }

13. 5) -What will be output? int *fun(); void main() { int *j; j=fun(); printf(“%d”,*j); } int *fun() { int k=35; return &k; }

14. 6)-what will be output? void increment(); void main() { increment(); increment(); } void increment() { auto int i=1; printf(“%d”,i); printf(“%d”,&i); }

15. 7)-Will error occur? void display(); void main() { goto label; printf(“ecb alumni”); } void display() { label: printf(“computer science”); }

16. Concept of return value void swap(int,int); void main() { int a=1,b=2; swap(a,b); printf(“%d%d”,a,b); } void swap(int x,int y) { int t; t=x; x=y; y=t; printf(“%d%d”,x,y); } void swap(int*,int*); void main() { int a=1,b=2; swap(&a,&b); printf(“%d%d”,a,b); } void swap(int *x,int *y) { int t; t=*x; *x=*y; *y=t; }

17. Recursive function is a function which contains a call to itself RECURSIVE FUNCTION

18. 8)-What will be output? /* Based on stack */ void main() { int a=1,b=2,c=3,d; printf(“%d%d%d%d”); }

19. DESCRIPTION int fact(int); void main() { int a=4; result=fact(a); printf(“factorial vauue is=%d”,result); } int fact(int x) { if(x==1) return 1; else return x*fact(x-1); }

20. 9)-Will error occur? void main() { int n; scanf(“%d”,n); printf(“%d”,fac()); } int fac(int n) { if(x==0) return 1; else return n*fac(n-1); }

21. 10)-What will be output? int i=1; void main() { if(i<=3) { i++; main(); } printf(“%d%d%d”,i,++i,i++); }

22. RECURSION V/S ITERATION Recursive solution is always logical and it is very difficult to trace. Recursion takes a lot of stack space. Recursive calling increase the space complexity. A recursive definition defines an object in simpler cases of itself reducing nested looping complexity. Every recursive problem can be done by iteration but vice versa is not always true.

23. THANKS ANY QUERY….?