In C, how does == behave when comparing an int and a float with equal numeric value? #include<stdio.h> int main() { int x = 3; float y = 3.0; if(x == y) printf("x and y are equal"); else printf("x and y are not equal"); return 0; }
-
Ax and y are equal
-
Bx and y are not equal
-
CUnpredictable
-
DNo output
-
ECompilation error
Answer
Correct Answer: x and y are equal
Explanation
Introduction / Context:This item checks the rules of the usual arithmetic conversions in C when comparing different types (int and float). It probes whether the integer is converted to a floating point value before the comparison.
Given Data / Assumptions:
- x is 3 (type int) and y is 3.0 (type float).
- The program uses
==to compare them and prints a message accordingly.
Concept / Approach:For the relational and equality operators, C applies the usual arithmetic conversions so both operands share a common type. With int and float, the int is converted to float. Therefore comparison becomes 3.0f == 3.0f which is true.
Step-by-Step Solution:Convert x to float: (float)3 → 3.0f.Compare 3.0f == 3.0f → true.The if branch executes and prints “x and y are equal”.
Verification / Alternative check:Changing y to 3.0000001f would likely make the comparison false after conversion. As written, exact equality holds with small integers representable exactly in float.
Why Other Options Are Wrong:“Not equal” contradicts conversion rules. “Unpredictable/No output/Compilation error” are not applicable.
Common Pitfalls:Believing that int and float are never equal; confusing floating-point rounding issues with integers exactly representable in float (all integers up to 2^24 are exactly representable in IEEE 754 single precision).
Final Answer:x and y are equal