Rearranging an array using JavaScript

Question

Rearranging an array using JavaScript

Looking to rearrange an array in a specific order:

Starting with the initial array:

const weekDaysArray = ['Mo', 'Tu', 'We', 'Th', 'Fr', 'Sa', 'Su'];

containing the days of the week in sequence, then obtaining a variable

const firstWeekday = Object.values(formattedReadsByDay)[0].dayOfWeek;

which holds a day of the week, let's say We for this example.

When it returns We, I want to change the array to:

weekDaysArray = ['We', 'Th', 'Fr', 'Sa', 'Su', 'Mo', 'Tu'];

I attempted

weekDaysArray [...weekDays.slice(-1), ...weekDays.slice(0, -1)]

but it didn't yield the desired result. Any suggestions?

javascript arrays

Answer 1

Answer №1

To proceed, follow these steps:

Determine the index of the first day.
Extract the portion of the array starting from the first day (inclusive) to the end. This becomes the new beginning of the week.
Retrieve the segment of the array starting from the beginning up to the first day (excluding it). This forms the new end of the week.
Combine both parts together.

These operations can be executed as shown below:

const weekDaysArray = ['Mo', 'Tu', 'We', 'Th', 'Fr', 'Sa', 'Su'];

const firstWeekday = "We";

//1. Find the index
const index = weekDaysArray.indexOf(firstWeekday);

//2. Obtain the start of the week
const startWeek = weekDaysArray.slice(index);
//3. Acquire the end of the week
const endWeek = weekDaysArray.slice(0, index);

//4. Merge the new week together
const result = [...startWeek, ...endWeek];

console.log(result);

Answer 2

To proceed, follow these steps:

Determine the index of the first day.
Extract the portion of the array starting from the first day (inclusive) to the end. This becomes the new beginning of the week.
Retrieve the segment of the array starting from the beginning up to the first day (excluding it). This forms the new end of the week.
Combine both parts together.

These operations can be executed as shown below:

const weekDaysArray = ['Mo', 'Tu', 'We', 'Th', 'Fr', 'Sa', 'Su'];

const firstWeekday = "We";

//1. Find the index
const index = weekDaysArray.indexOf(firstWeekday);

//2. Obtain the start of the week
const startWeek = weekDaysArray.slice(index);
//3. Acquire the end of the week
const endWeek = weekDaysArray.slice(0, index);

//4. Merge the new week together
const result = [...startWeek, ...endWeek];

console.log(result);

Answer 3

Answer №2

To reorganize the array by moving the first item to the end, you can use the code snippet

weekDaysArray.push(weekDaysArray.shift())

. This operation transforms an array like [1, 2, 3] into [2, 3, 1]. Afterwards, check if the first element in the array matches your desired day with weekDaysArray[0] == your day. If it does, return the modified array. If not, repeat the same operation one more time.

Answer 4

To reorganize the array by moving the first item to the end, you can use the code snippet

weekDaysArray.push(weekDaysArray.shift())

. This operation transforms an array like [1, 2, 3] into [2, 3, 1]. Afterwards, check if the first element in the array matches your desired day with weekDaysArray[0] == your day. If it does, return the modified array. If not, repeat the same operation one more time.

Answer 5

Answer №3

Here's a possible implementation based on the response provided by Dima Vak:

function organizeWeekdays (initialDay) {
    const daysOfWeek = ['Mo', 'Tu', 'We', 'Th', 'Fr', 'Sa', 'Su'];

    for(let i = 0; i < daysOfWeek.length; i++) {
        if (daysOfWeek[0] === initialDay) break;
        daysOfWeek.push(daysOfWeek.shift())
    }

    return daysOfWeek;
}

const startingDay = Object.values(formattedReadsByDay)[0].dayOfWeek;
console.log({
    result: organizeWeekdays(startingDay)
});

Answer 6

Here's a possible implementation based on the response provided by Dima Vak:

function organizeWeekdays (initialDay) {
    const daysOfWeek = ['Mo', 'Tu', 'We', 'Th', 'Fr', 'Sa', 'Su'];

    for(let i = 0; i < daysOfWeek.length; i++) {
        if (daysOfWeek[0] === initialDay) break;
        daysOfWeek.push(daysOfWeek.shift())
    }

    return daysOfWeek;
}

const startingDay = Object.values(formattedReadsByDay)[0].dayOfWeek;
console.log({
    result: organizeWeekdays(startingDay)
});

Rearranging an array using JavaScript

Answer №1

Answer №2

Answer №3

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