Taking each four digit number of an array in turn, return the number that you are on when all of the digits 0-9 have been discovered. If not all of the digits can be found, return "Missing digits!"
I've tried to loop through then set a conditional if (i != i+1) push into new array this just gave me the array, it's apparent my logic is wrong. could anyone help me out
For example calling this function with
arr = findAllDigits([5175, 4538, 2926, 5057, 6401, 4376, 2280, 6137, 8798, 9083])
the code should return 5057.
While calling
arr = findAllDigits([4883, 3876, 7769, 9846, 9546, 9634, 9696, 2832, 6822, 6868])
should return "missing numbers"
function findAllDigits(arr) {
newArr = [];
for (let i = 0; i < arr.length; i++) {
if (arr[i] != arr[i + 1]) newArr.push(arr[i]);
console.log(newArr);
}
}
Do I need to split because it is taking everything before the comma as one number, then iterate over?
You can use Set here
Loop over the array and then create a set, You have to return the current number if set size becomes 10 because you need to check 0-9
function findAllDigits(arr) {
const set = new Set();
for (let n of arr) {
String(n)
.split("")
.forEach((c) => set.add(c));
if (set.size === 10) return n;
}
return "Missing digits!";
}
const arr1 = [5175, 4538, 2926, 5057, 6401, 4376, 2280, 6137, 8798, 9083];
const arr2 = [4883, 3876, 7769, 9846, 9546, 9634, 9696, 2832, 6822, 6868];
console.log(findAllDigits(arr1));
console.log(findAllDigits(arr2));Your for loop is only checking to see if the array entry is equal to the next one. You need to split up the digits inside each entry and store them individually:
function findAllDigits(arr) {
newArr = [];
for (let i = 0; i < arr.length; i++) {
// now iterate the individual digits
const entryAsString = arr[i].toString();
for (let j = 0; j < entryAsString.length; j++) {
// if we haven't seen the digit before, add it to the array
if(!newArr.includes(j) {
newArr.push(j);
}
}
// we know we have all digits when newArr is 10 entries long
if (newArr.length) {
console.log(arr[i]);
// you can also return this value here
}
}
}
One more solution:
const arr1 = [5175, 4538, 2926, 5057, 6401, 4376, 2280, 6137, 8798, 9083];
const arr2 = [4883, 3876, 7769, 9846, 9546, 9634, 9696, 2832, 6822, 6868];
const findAllDigits = (arr) => {
// Declare new Set: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Set
const digits = new Set();
// return the first item from array that fits the condition,
// find() method: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/find
return arr.find((curr) => (
// String(5175) -> '5175' : https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String
// [...'5175'] -> ['5','1','7','5'] : https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Spread_syntax
// .forEach(digits.add, digits) - forEach with callback function and context : https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/forEach
// comma operator lets get rid of return : https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Comma_Operator
[...String(curr)].forEach(digits.add, digits),
// condition - is find() method need to return an item
(digits.size === 10)
// if returned value is not undefined or null return finded number oterwise error string
// https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Nullish_coalescing_operator
)) ?? "Missing digits!";
};
console.log(findAllDigits(arr1)); //5057
console.log(findAllDigits(arr2)); //Missing digits!