JavaScript: Get the week start date

JavaScript Datetime: Exercise-50 with Solution

Week Start Date

Write a JavaScript function to get the week's start date.

Sample Solution:

JavaScript Code:

// Define a function startOfWeek that takes a Date object date as input
function startOfWeek(date)
{
  // Calculate the difference between the date's day of the month and its day of the week
  var diff = date.getDate() - date.getDay() + (date.getDay() === 0 ? -6 : 1);

  // Set the date to the start of the week by setting it to the calculated difference
  return new Date(date.setDate(diff));
}

// Create a new Date object representing the current date and time
dt = new Date(); 

// Output the start of the week for the current date and time
console.log(startOfWeek(dt).toString());

Output:

Mon Jun 18 2018 18:22:59 GMT+0530 (India Standard Time)

Explanation:

In the exercise above,

• The function "startOfWeek()" takes a "Date" object 'date' as input.
• It calculates the difference between the day of the month ('date.getDate()') and the day of the week ('date.getDay()').
• If the day of the week is Sunday (0), it adjusts the difference to ensure the start of the week is considered Monday.
• It then sets the date to the start of the week by modifying it with the calculated difference.
• Finally, it returns a new "Date" object representing the start of the week.

Flowchart:

Live Demo:

See the Pen JavaScript - Get the week start date-date-ex-50 by w3resource (@w3resource) on CodePen.

For more Practice: Solve these Related Problems:

• Write a JavaScript function that calculates the start date (Monday) of the week for a given Date object.
• Write a JavaScript function that adjusts a given date to the previous Monday if it is not already Monday.
• Write a JavaScript function that returns the week start date in "MM/DD/YYYY" format.
• Write a JavaScript function that validates the date input and handles cases where the input is already the week’s start.

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