C - Review II 6,7

6. What's the "condition" so that the following code snippet prints both HelloWorld !

if "condition"
printf ("Hello");
else
printf("World");

Answer: “condition” can replaced by !printf(“Hello”);
or printf(“Hello”)&&0
or printf(“Hello”), 0
Any expression with commas will take the final value as the expression value.

7. main(){

int i=5;

printf(“%d”,i++ * i++);

i = 5;

printf(“%d”,++i * i++);

i = 5;

printf(“%d”,i++ * ++i);

i=5;

printf(“%d”,++i * ++i);

}

Ouput: 25 36 36 49

When a variable is modified more than once in an expression it takes same value(infact final value) for all the uses or that variable.