Common operations on arrays

arrayOperations.js

/* 
 * =================================
 * =========== SEARCH ============== 
 * =================================
*/

let array = [1, 2, 3, 4, 5]

let val = array.find((val) => {
	if (val === 1) {
		return true
	}
})

// val = 1
// array = [1, 2, 3, 4, 5]

// same thing, but written more succintly
// let val = array.find((val) => return val === 1)


/* 
 * =================================
 * =========== FILTER ============== 
 * =================================
*/


let array = [1, 2, 3, 4, 5]

let val = array.filter((val) => { // 1
	if (val % 2 === 0) { // is it even?
		return true
	}
})

// val = [2, 4]
// array = [1, 2, 3, 4, 5]

// same thing, but written more succintly
// let val = array.filter((val) => return val % 2 === 0)


/* 
 * =================================
 * =========== MODIFY ============== 
 * =================================
*/


let array = [1, 2, 3, 4, 5]

let newList = array.map((val) => {
	return val + 1
})

// newList = [2, 3, 4, 5, 6]
// array = [1, 2, 3, 4, 5]

// same thing, but written more succintly
// let newList = array.map((val) => val + 1)


/* 
 * =================================
 * =========== OTHER ============== 
 * =================================
*/

// This is a forEach function. It isn't as much an array 'search', 'modify', or 'filter' option.
// It's more of a shorthand for a for loop. This allows you to go through
// each item in an array without having to write list[i] and declare and increment i


let emptyList = []

array.forEach((val) => {
	emptyList.push(val)
})

// emptyList = [6, 7, 8, 9, 10]
// array = [1, 2, 3, 4, 5]