Java 8 - Lambda Expression Rule

There are some rules to make lambda expression more concise.

Example 1:

Let's take an example:

public void displaySum(int a, int b) {
    System.out.println(a + b);
}

The valid Lambda expression of above method is:

(int a, int b) -> System.out.println(a + b);

It can be made more concise by taking out the parameter's datatypes.

(a, b) -> System.out.println(a + b);

Note: The type of the parameters can be declared explicitly, or it can be inferred from the context.

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Example 2:

Let's take another example:

public int square(int a) {
    return a * a;
}

Its equivalent lambda expression is:

n->n*n;

Note:
1. If there are no curly brackets, then the return keyword is not needed.
2. If there is only one parameter in the function, then () is also not needed.

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Q1. Write an lambda expression that returns length of string.

Give answer on the comment below :)

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How to execute the Lambda expression?

To execute the lambda expression, we use one of the other features of java 8: Functional Interface. We will discuss it in the next post of this series.

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