Function expression

function expression - a way of defining a function as a variable or value

I practiced function expression using the examples below:

Example 1 – Assigned to a Variable

const hello = function(){
    console.log("Hello there");
};
hello();

Final output:

Hello there

What This Code Does:

Stores a function in the variable hello.
Calls the function by using hello().

Example 2: Passed as a Parameter

const numbers = [1, 2, 3 , 4, 5, 6, 8, 9, 10, 11, 12]; 
const evenNums = numbers.filter(function(element){
    return element % 2 === 0;
});
console.log(evenNums);

Final output:

[2, 4, 6, 8, 10, 12]

What This Code Does:

function passed as a parameter to .filter()
Anonymous function used as a callback
.filter() takes this function and uses it to test each element in the numbers array.

What I Learned:

Function expressions allow us to:

• Store functions in variables.
• Pass them as arguments.
• Use them inside array methods like .map(), .filter(), .reduce(), and setTimeout().