JavaScript: Minimum date from an array of dates

JavaScript Datetime: Exercise-12 with Solution

Write a JavaScript function to get the minimum date from an array of dates.

Test Data:
console.log(min_date(['2015/02/01', '2015/02/02', '2015/01/03']));
Output :
"2015/01/03"

Sample Solution:

JavaScript Code:

// Define a JavaScript function called min_date with parameter all_dates
function min_date(all_dates) {
  // Initialize variables to store the minimum date and its corresponding Date object
  var min_dt = all_dates[0],
      min_dtObj = new Date(all_dates[0]);
  
  // Iterate through each date in the array using forEach method
  all_dates.forEach(function(dt, index) {
    // Convert the current date string to a Date object
    var current_dtObj = new Date(dt);

    // Compare the current Date object with the minimum Date object
    if (current_dtObj < min_dtObj) {
      // If the current Date object is less than the minimum Date object, update the minimum date
      min_dt = dt;
      min_dtObj = new Date(dt);
    }
  });

  // Return the minimum date
  return min_dt;
}

// Output the minimum date from the provided array of dates
console.log(min_date(['2015/02/01', '2015/02/02', '2015/01/03']));

Output:

2015/01/03

Explanation:

In the exercise above,

• The code defines a JavaScript function named "min_date()" with one parameter 'all_dates', representing an array of date strings.
• Inside the function:
• It initializes two variables: 'min_dt' to store the minimum date string found so far and 'min_dtObj' to store the corresponding Date object of the minimum date.
• It converts the first date string in the 'all_dates' array to a Date object and assigns it to 'min_dtObj'.
• It iterates through each date string in the 'all_dates' array using the "forEach()" method.
• Inside the loop:
• It converts the current date string to a Date object.
• It compares the current Date object with the minimum Date object (min_dtObj).
• If the current Date object is less than 'min_dtObj', it updates 'min_dt' and 'min_dtObj' to the current date string and Date object, respectively.
• After iterating through all date strings, it returns the minimum date ('min_dt').
• The code then demonstrates the "min_date()" function by calling it with an array of date strings ['2015/02/01', '2015/02/02', '2015/01/03'].

Flowchart:

Live Demo:

See the Pen JavaScript - Minimum date from an array of dates-date-ex- 12 by w3resource (@w3resource) on CodePen.

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