Lambda expressions in Java can return values just like regular methods. This makes them ideal for implementing functions that perform a task and return a result, such as calculations, transformations, or comparisons.
Syntax of Lambda with Return Value
(parameters) -> expression
// or with block body
(parameters) -> {
// multiple statements
return result;
}Code language: JavaScript (javascript)- If the lambda has one expression, the result of that expression is automatically returned.
- If the lambda has multiple statements, you must use the
returnkeyword explicitly.
Program: Compare Two Numbers
interface Compare {
int max(int a, int b);
}
public class LambdaReturnExample {
public static void main(String[] args) {
Compare cmp = (a, b) -> {
if (a > b) return a;
else return b;
};
System.out.println("Max: " + cmp.max(25, 40));
}
}Program : Check Palindrome
interface PalindromeCheck {
boolean isPalindrome(String str);
}
public class LambdaReturnExample {
public static void main(String[] args) {
PalindromeCheck pc = s -> s.equals(new StringBuilder(s).reverse().toString());
System.out.println("Is Palindrome: " + pc.isPalindrome("madam"));
}
}Lambda expressions with return values in Java allow for clean, concise implementations of functional logic. By using either a simple expression or a block of code with a return statement, you can:
- Replace anonymous classes
- Simplify business logic
- Improve readability
These are especially powerful in stream operations and functional programming constructs where operations often need to return transformed or computed results.