To calculate a person’s age from someone’s birthday with JavaScript, we can use native JavaScript date methods.
For instance, we can write:
const getAge = (d1, d2 = new Date()) => {
const diff = d2.getTime() - d1.getTime();
return Math.floor(diff / (1000 * 60 * 60 * 24 * 365.25));
}
console.log(getAge(new Date(1988, 10, 3)));
We create the getAge function that takes 2 dates d1 and d2 .
Then we subtract the timestamps of them that we got with getTime with:
const diff = d2.getTime() - d1.getTime();
And then we divide diff with 1000 * 60 * 60 * 24 * 365.25 to convert diff to the number of years differences, which is the person’s age.
Therefore, the console log should log 32.
