In this tutorial, we are going to learn about how to get the first digit of a number in Java.
To get the first digit of a number, convert the number to a string and call the
substring() method on it, by passing the
0, 1 as a arguments.
substring() method returns the first character of a string then convert the result back to a number to get the first digit.
Here is an example:
int price = 429; String priceStr = Integer.toString(price); int firstDigit = Integer.parseInt(priceStr.substring(0,1)); System.out.println(firstDigit);
In the example above, on the first step we have converted the number to string, so we can call a substring() method on it.
We have passed the
0, 1 as arguments to the substring() method, so the extraction starts at index 0 and ends before index 1.
Note: Strings are sequence of characters, where indexes are zero-based. The first character is in position 0, the second in 1, and so on.