- Write a function
forEachElemthat takes in an array and a callback. Call the callback on each element in the array.
function forEachElem(arr, callback){
for (let i = 0; i < arr.length; i++){
callback(arr[i])
}
}
- Create a function logEachElem that takes an array as an argument, and uses the
forEachElemmethod to log each element of the array.
function logEachElem(arr) {
forEachElem(arr, el => {
console.log(el)
})
}
- Create a function
logArrTypesthat uses theforEachElemmethod to log each array element followed by its type. For example:
function forEachElem(arr, callback){
for (let i = 0; i < arr.length; i++){
callback(arr[i])
}
}
function logArrTypes(arr){
forEachElem(arr, el => {
console.log(el + ' is a ' + typeof el);
})
}
console.log(logArrTypes([1,'dog',true]));
let mixedArr = [1, 'cat', true]
logArrTypes(mixedArr)
// will log:
// 1 is a number
// 'cat' is a string
// true is a boolean- Write a function
myMapthat takes in an array and a callback. Call the callback on each element of the array and add the result to an output array. Return the output array.
function myMap(arr, callback){
let output = [];
for(let i = 0; i < arr.length; i++){
output.push(callback(arr[i]));
}
return output
}
console.log(myMap([1,2,3]));
- Create a function
allCapsthat takes in an array as an argument, and uses themyMapfunction to return all the elements capitalized.
function myMap(arr, callback){
let output = [];
for(let i = 0; i < arr.length; i++){
output.push(callback(arr[i]));
}
return output
}
function allCaps(arr){
myMap(arr, el =>{
console.log(el.toUpperCase(arr));
})
}
console.log(allCaps(['hello']));
- You are given the following functions:
function conservativeSpender(balance) {
return balance > 100
}
function liberalSpender(balance) {
return balance > 10
}
function horribleSaver (balance) {
return balance > 0
}Write a function shouldIBuyThis that takes in a balance and a callback (one of the above functions). The fuction should return either
"Sure! I've got the money!" or "Nope! Gotta keep my savings up!"
console.log(shouldIBuyThis(20, horribleSaver))
// logs: "Sure! I've got the money!"
console.log(shouldIBuyThis(20, liberalSpender))
// logs: "Sure! I've got the money!"
console.log(shouldIBuyThis(20, conservativeSpender))
// logs: "Nope! Gotta keep my savings up!"
console.log(shouldIBuyThis(101, conservativeSpender))
// logs: "Sure! I've got the money!"function conservativeSpender(balance) {
return balance > 100
}
function liberalSpender(balance) {
return balance > 10
}
function horribleSaver (balance) {
return balance > 0
}
function shouldIBuyThis(balance,callback) {
if (callback(balance)){
return 'sure I got money'
} else {
return 'nope, gotta keep my saving up'
}
}
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