.foreach

Applies a function to each item in the array

[1,2,3].forEach(x => console.log(x))

<!-- returns:-->
1
2
3

.map

Applies a function to each item in the array -and then creates a new array with the results of applying the function to each value

[1,2,3].map(x => (x => x + 1))

<!- returns -->
2,3,4

.filter

Same as .map but this is a test function, if it passed, it goes into the ‘collection’ or result

[1,2,3].map(x=>(x=> x > 1))

<!- returns -->
2,3