Get the first digit of a number in Java

In this tutorial, we are going to learn about how to get the first digit of a number in Java.

Get the first digit of a number

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.

The 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);

Output:

4

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.

References

• Strings in Java

• Integers in Java