I want to evaluate whether the number is under than 10, having as an answer an array of booleans. I tried using forEach, map, but I didn't succeed in any attempt.
function underTen (arr){
let underTenAnswer = arr.forEach(function(n){
if (n < 10) {
true;
} else {
false;
}
})
}
Input: underTen([1,9,12,19,4,16] Expected outcome: Array [True, True, False, False, True, False]
I'm a beginner, sorry if something is notoriously incorrect.
There is a really quick way to do this:
let a = [1, 2, 3, 4, 5, 6, 7];
let b = [1, 2, 3, 4, 12, 8];
console.log(a.every((x) => x < 10)) // true
console.log(b.every((x) => x < 10)) // falseWe use Array.every() here to check if each array element passes some condition.
If you need to return an array of booleans, then you can use Array.map():
let b = [1, 2, 3, 4, 12, 8];
console.log(b.map((x) => x < 10)) // [true, true, true, true, false, true]Edit 2: I thought I misunderstood the question but it seems this is what the OP wanted.
You can use the array helper every if you want to know if all array values match an expression:
array.every(number => number < 10);
Edit: I misunderstood the question.
To get an array with boolean values according to an expression applied to each value:
const newArray = array.map(number => number < 10);
The question suggests the output is to be an array with boolean values corresponding to each value in the test array.
Array.map() is ideally suited to this problem. Working snippet:
const testArray = [1,9,12,19,4,16];
const resultsArray = testArray.map(element => (element < 10))
console.log(resultsArray)