[Solved] Identify the error in this interface declaration:interface Calculator { int add(int a, int b) { return a + b; } } | Java

Java - Interfaces

Identify the error in this interface declaration:

interface Calculator {
    int add(int a, int b) {
        return a + b;
    }
}

AInterfaces cannot have method bodies unless default or static

BMethod name 'add' is invalid in interfaces

CReturn type 'int' is not allowed in interfaces

DInterface name must start with lowercase

Step-by-Step Solution

Solution:

Step 1: Check method body rules in interfaces
In Java, interface methods cannot have bodies unless marked as default or static.
Step 2: Analyze the given method
The method add has a body but no default or static keyword, causing a syntax error.
Final Answer:
Interfaces cannot have method bodies unless default or static -> Option A
Quick Check:
Method bodies in interfaces need default/static [OK]

Quick Trick: Interface methods need default/static for bodies [OK]

Common Mistakes:

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