How to Accurately Calculate Age from a YYYYMMDD Birthdate?

Calculate Age Using Birth Date in YYYYMMDD Format

Question:

How can we accurately determine an individual's age given their birth date in the YYYYMMDD format using the Date() function?

Improved Solution:

The provided code snippet for calculating age can be refined for better efficiency and correctness:

function getAge(dateString) {
    var today = new Date();
    var birthDate = new Date(dateString);
    var age = today.getFullYear() - birthDate.getFullYear();
    var m = today.getMonth() - birthDate.getMonth();
    if (m < 0 || (m === 0 && today.getDate() < birthDate.getDate())) {
        age--;
    }
    return age;
}

Explanation:

• The getAge() function accepts a dateString in the YYYYMMDD format.
• It creates Date objects for the current date (today) and the birth date (birthDate) using new Date().
• The initial age is calculated as the difference between the current year and the birth year.
• The month difference (m) is determined by subtracting the birth month from the current month.
• If m is less than 0 or if m is 0 and the current day is less than the birth day, the age is decremented by 1 to account for incomplete years.
• The resulting age is returned, providing a more precise calculation than the original code.

This solution addresses the inaccuracy of the original code in handling dates that occur before the current month or day, ensuring a correct age calculation for all scenarios.

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