By : Nanda Kishor K N Mail ID : nandakishorkn@rediffmail.com_________________________________________________________________________________________________ C For Swimmers ______________ If u don't know how to swim, learn it now. Otherwise participate in the competition._________________________________________________________________________________________________ Topic : Playing with 'printf()' statement _____ _____________________________________************************************************************************************************** NOTE : All the programs are tested under Turbo C/C++ compilers. ** It is assumed that,** *=> Programs run under DOS environment,** *=> The underlying machine is an x86 system,** *=> Necessary header files are included.** *=> Program is compiled using Turbo C/C++ compiler.** The program output may depend on the information based on this assumptions. ** (For example sizeof(int) = 2 bytes may be assumed). **************************************************************************************************[Q001]. What will be the output of the following program :void main() { printf(); }(a)Run-Time Error (b)Compile-Time Error (c)No Output(d)None of theseAns. (b) Since there must be enough arguments for the format._________________________________________________________________________________________________[Q002]. What will be the output of the following program : void main() { printf(NULL); }(a)Run-Time Error (b)Compile-Time Error (c)No Output(d)None of theseAns. (c) Since NULL is a constant value or NULL pointer value or a NULL string._________________________________________________________________________________________________[Q003]. What will be the output of the following program : void main() { printf("%%",7); }(a)7 (b)Compile-Time Error (c)%(d)%%Ans. (c) Since % is a format specifier & excess arguments (more than required by the format) aremerely ignored._________________________________________________________________________________________________[Q004]. What will be the output of the following program : void main() { printf("//",5); }(a)5 (b)Compile-Time Error (c)/(d)//Ans. (d) Since / is an escape sequence character & excess arguments (more than required by the format) are merely ignored._________________________________________________________________________________________________[Q005]. What will be the output of the following program : void main() { printf("d%",8); }(a)8 (b)Compile-Time Error (c)d%(d)None of theseAns. (c) Since excess arguments (more than required by the format) are merely ignored._________________________________________________________________________________________________[Q006]. What will be the output of the following program : void main() { printf("%d"+0,123); }(a)123 (b)Compile-Time Error (c)No Output(d)None of theseAns. (a) "%d"+0 has no effect on the output operation. _________________________________________________________________________________________________[Q007]. What will be the output of the following program : void main() { printf("%d"+1,123); }(a)123 (b)Compile-Time Error (c)d(d)No OutputAns. (c) "%d"+1 (i.e 1 or > 0) affects the program output by considering "%d" as string and ignores 123Where 1 refers to the index i.e. 2nd character in the array or string "%d"._________________________________________________________________________________________________[Q008]. What will be the output of the following program : void main() { printf("%d",printf("Hi!")+printf("Bye")); }(a)ByeHi!6 (b)Hi!Bye6 (c)Compile-Time Error(d)None of theseAns. (b) Since L->R priority & the length of the strings 'Hi!' & 'Bye' is 3+3=6_________________________________________________________________________________________________[Q009]. What will be the output of the following program : void main() { printf("%d",printf("Hi!")*printf("Bye")); }(a)ByeHi!6 (b)Hi!Bye9 (c)Hi!Bye(d)None of theseAns. (b) Since L->R priority & the length of the strings 'Hi!' & 'Bye' is 3*3=9_________________________________________________________________________________________________[Q010]. What will be the output of the following program : void main() { printf("%d",printf("")+printf("")); }(a)0 (b)No Output (c)Compile-Time Error(d)None of theseAns. (a) Since L->R priority & the length of the 2 empty strings are : 0+0=0_________________________________________________________________________________________________[Q011]. What will be the output of the following program : void main() { printf("Hi Friends"+3); }(a)Hi Friends (b)Friends (c)Hi Friends3(d)None of theseAns. (b) Since (base adress)+0 points to the value 'H'. Now the NEW (base address) equals(base address)+3 that points to the character 'F'. Thus it prints the string from 'F' onwards._________________________________________________________________________________________________[Q012]. What will be the output of the following program : void main() { printf("C For ") + printf("Swimmers"); }(a)Compile-Time Error (b)C For Swimmers (c)Run-Time Error(d)None of theseAns. (b) It is a VALID C statement. Change the operators but the output remains same(NO EFFECT)._________________________________________________________________________________________________[Q013]. What will be the output of the following program : void main() { printf("\/\*\-*\/"); }(a)Run-Time Error (b)\/*-*\/ (c)/*-*/(d)None of theseAns. (c) Since \ is an escape sequence character. Be careful while analyzing such statements._________________________________________________________________________________________________[Q014]. What will be the output of the following program : int main() { int main=7; { printf("%d",main); return main; } printf("Bye"); }(a)Compile-Time Error (b)Run-Time Error (c)7Bye(d)7Ans. (d) It is a VALID C statement. Prints 7 and returns the same to the OS. NOTE: Last printfstatement will not be executed._________________________________________________________________________________________________[Q015]. What will be the output of the following program : void main() { main(); }(a)Compile-Time Error (b)Run-Time Error (c)Infinite Loop(d)None of theseAns. (c) It is a VALID C statement. It is like a recursive function & the statements get executedinfinite number of times._________________________________________________________________________________________________[Q016]. What will be the output of the following program : void main() { printf("Work" "Hard"); }(a)Work (b)Hard (c)No Output(d)WorkHardAns. (d) Since L->R priority. First it prints the word 'Work' & then 'Hard'._________________________________________________________________________________________________[Q017]. What will be the output of the following program : void main() { char str[]="%d"; int val=25; printf(str,val); }(a)Compile-Time Error (b)Run-Time Error (c)25(d)None of theseAns. (c) It is a VALID C statement. First parameter contains the format specifier & the Secondparameter contains the actual value 25._________________________________________________________________________________________________[Q018]. What will be the output of the following program : void main() { int val=75; printf("%d",val,.,.); }(a)Compile-Time Error (b)Unpredictable (c)75(d)None of theseAns. (b) Output is Unpredictable B'coz there are not enough arguments for the format. But it is aVALID C statement._________________________________________________________________________________________________[Q019]. What will be the output of the following program : void main() { int val=10; printf("%d",val+1,"%d",val--); }(a)10 (b)11 10 (c)11 9(d)10 9Ans. (a) Since R->L priority. The second format specifier '%d' is an excess argument and it isignored._________________________________________________________________________________________________[Q020]. What will be the output of the following program : void main() { int val=5; printf("%d %d %d %d",val,--val,++val,val--); }(a)3 4 6 5 (b)5 5 6 5 (c)4 4 5 5(d)None of theseAns. (c) Since R->L priority._________________________________________________________________________________________________[Q021]. What will be the output of the following program : void main() { int val=5,num; printf("%d",scanf("%d %d",&val,&num)); }[NOTE : ASSUME 2 values are entered by the user are stored in the variables 'val' & 'num' respectively.](a)1 (b)2 (c)5(d)None of theseAns. (b) Since scanf statement returns the number of input fields successfully scanned, converted& stored._________________________________________________________________________________________________[Q022]. What will be the output of the following program :#define Compute(x,y,z) (x+y-z) void main() { int x=2,y=3,z=4; printf("%d",Compute(y,z,(-x+y)) * Compute(z,x,(-y+z))); }(a)40 (b)30 (c)Compile-Time Error(d)None of theseAns. (b) Since it is macro function. NOTE : Be careful while doing such type of calculations._________________________________________________________________________________________________[Q023]. What will be the output of the following program : void main() { int m=10,n=20; printf("%d %d %d",m/* m-value */,/* n-value */n,m*/* Compute m*n */n); }(a)Run-Time Error (b)10 20 200 (c)Compile-Time Error(d)None of theseAns. (b) Since comments /*...*/ are ignored by the compiler._________________________________________________________________________________________________[Q024]. What will be the output of the following program : void main() { int m=10,n=20; /* printf("%d",m*n); }(a)VALID but No Output (b)VALID : Prints 200 (c)Compile-Time Error(d)None of theseAns. (c) Since COMMENT statement not ended properly i.e */ is missing in the above program._________________________________________________________________________________________________[Q025]. What will be the output of the following program : void main() { int val=97; "Printing..."+printf("%c",val); }(a)Printing...97 (b)97 (c)Compile-Time Error(d)a Ans. (d) Since alphabet 'a' is the ASCII equivalent of 97._________________________________________________________________________________________________[Q026]. What will be the output of the following program : void main() { int val=5; val=printf("C") + printf("Skills"); printf("%d",val); }(a)Skills5 (b)C1 (c)Compile-Time Error(d)CSkills7 Ans. (d) VALID Since 'printf' function return the no. of bytes output._________________________________________________________________________________________________[Q027]. What will be the output of the following program : void main() { char str[]="Test"; if ((printf("%s",str)) == 4) printf("Success"); elseprintf("Failure"); }(a)TestFailure (b)TestSuccess (c)Compile-Time Error(d)Test Ans. (b) VALID Since 'printf' function return the no. of bytes output._________________________________________________________________________________________________[Q028]. What will be the output of the following program : void main() { int val=5; printf("%*d",val); }(a) 5 (b)5 (c)Compile-Time Error(d)None of these Ans. (a) VALID Since '*' specifies the precision (i.e. the next argument in the precision). If noprecision is specified then the value itself will be the precision value. Thus it prints 5 BLANKSPACES & then the value 5._________________________________________________________________________________________________[Q029]. What will be the output of the following program : void main() { int val=5; printf("%d5",val); }(a)Compile-Time Error (b)5 (c)55(d) 5 Ans. (c) _________________________________________________________________________________________________[Q030]. What will be the output of the following program : void main() } int val=5; printf("%d",5+val++); {(a)Compile-Time Error (b)5 (c)10(d)11Ans. (a) Since incorrect usage of pair of braces } and {. Correct usage : Each compound statementshould be enclosed within a pair of braces, i.e { and }._________________________________________________________________________________________________Thanx for using "C For Swimmers".Regarding this material, you can send Bug Reports, Suggestions, Comments,etc. to nandakishorkn@rediffmail.com