I've got a problema running now that is: I need a function that find the highest number made by consecutive digits within that number that I received by the parameter. For example: If my input is 1235789 my output should be 789. If my input is 123689, my output should be 123.
function getbiggestNumber(numberInput) {
const numberString = numberInput.toString(); // turned into string
const temporaryResult = []; // create the array of possible solutions which i'd go through to find the highest value inside of it
for (let i = 0; i < numberString.length; i += 1) {
const temporary = [numberString[i]]; // create a temporary answer that would serve as a base
for (let x = i + 1; x < numberString.length; x += 1) {
const subResult = Number(numberString[i]) - Number(numberString[x]); // the result of the current number minus the following number
if (subResult === -1) { // if they are in a sequence this should be -1
temporary.push(numberString[x]); // pushing this number to that temporary answer
} // here should be some condition for it to keep running, instead getting into another number of for loop
}
temporaryResult.push(temporary); // pushing that temporary answer to the result, so I could keep track of it
}
console.log(temporaryResult); // checking the output
}
The problem is that this code is only providing double digits inside a array, and that was the only way I found to do this. I'd be really thankful if someone could give me a light on this. Thanks!
That looks a bit unnecessarily convoluted. I'd just split the string into chunks based on sequential digits, then call Math.max on all.
const getBiggestNumber = (numberInput) => {
const digits = [...String(numberInput)].map(Number);
const chunks = [];
let lastDigit;
let chunk = [];
for (const digit of digits) {
if (lastDigit === digit - 1) {
// Continuation of sequence
chunk.push(digit);
} else {
if (chunk.length) chunks.push(chunk);
// New sequence:
chunk = [digit];
}
lastDigit = digit;
}
chunks.push(chunk);
return Math.max(
...chunks.map(chunk => Number(chunk.join('')))
);
};
console.log(getBiggestNumber(1235789));Another approach:
const largestStreak = (input) => Math .max (... [...String (input)] .map (Number) .reduce (
(a, d, i, xs) =>
d == a .at (-1) .at (-1) + 1
? [... a .slice (0, -1), [... a .at (-1), d]]
: [... a, [d]],
[[]]
) .map (ns => Number (ns .join (''))))
console .log (largestStreak (1235789))
console .log (largestStreak (1235689))This goes through the following steps:
input:
1235789
[...String (input)] .map (Number):
[1, 2, 3, 4, 7, 8, 9]
reduce accumulator, step-by-step:
[[]]
[[], [1]]
[[], [1, 2]]
[[], [1, 2, 3]]
[[], [1, 2, 3], [5]]
[[], [1, 2, 3], [5], [7]]
[[], [1, 2, 3], [5], [7, 8]]
[[], [1, 2, 3], [5], [7, 8, 9]]
.map (ns => Number (ns .join (''))):
[0, 123, 5, 789]
Math .max (...):
789