JavaScript Lambdas

In JavaScript, Lambda is kind of an anonymous function with reduced syntax that looks clutter free.

Syntax

The syntax of a lambda is

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(parameters) => returnValue
//or
(parameters) => { returnValue }

This lambda function can be passed as an argument in another function call.

Examples

An example for a lambda function that takes two parameters: a and b, and returns a value: a + b is

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(a, b) => a + b
//or
(a, b) => {a + b}

An example for a lambda function that takes no parameters, and returns a value x is

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() => x

An example for a lambda function that takes a single parameter: a, and returns a value a * a is

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(a) => a * a
//or
a => a * a

In the following example script, we write a lambda function that takes an integer number as argument and returns a boolean value of true if the number is even, or false if the number is odd.

index.html

<!DOCTYPE html>
<html lang="en">
<body>
    <pre id="output"></pre>
    <script>
        var add = (a, b) => a + b;
        var n1 = 4, n2 = 3;
        var sum = add(n1, n2);
        document.getElementById('output').innerHTML = n1 + ' + ' + n2 + ' = ' + sum;
    </script>
</body>
</html>

Conclusion

In this JavaScript Tutorial, we have learnt about Lambdas: how to define a lambda function, how to accept parameters and return a value, with examples.

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JavaScript Lambdas