java

Reverse Digits()

Parameters: int number

The number to be reversed

Returns: A reversed version of the input number

This is a simple Java program used to reverse the digits of a given number using a while loop and mathematical operations.

Variables
While loop
Medium dificulty

How to Code a Reverse Digits Function in Java

Hello, fellow programmer! Welcome to this blog post. Today we are going to delve into how a function can be written in Java to reverse the digits of any given number. Without the use of any jargon or terminology specific to a region, this guide will walk you through each step in a simple, yet comprehensive manner. Stay tuned and sharpen your coding skills. Grab a cup of coffee, make yourself comfortable and off we go on this intriguing journey!

Step 1: Defining the Function

The first thing we need to do is define the function. In Java, we typically do this using the public static keywords, followed by the return type of the function (int in this case as we are dealing with integer numbers), the name of the function we want to create (reverseDigits), and any parameters we want to pass in. In this case, we'll pass in the number we want to reverse as an int.

public static int reverseDigits(int num) {
}

Step 2: Initializing the reversed Number

To reverse the digits of a number, you can initialize another integer for storing the reversed number. We'll start it at 0.

public static int reverseDigits(int num) {
int reversed = 0;
}

Step 3: Reverse Logic

In inside of the function, we need to implement the logic for reversing a number. This can be achieved using a while loop that will keep executing until num becomes 0. Inside the loop, each digit of a number is extracted, and the reversed number is computed.

public static int reverseDigits(int num) {
int reversed = 0;
while(num != 0) {
int digit = num % 10;
reversed = reversed * 10 + digit;
num /= 10;
}
}

Step 4: Return the reversed number

Finally, the function should return the reversed number.

public static int reverseDigits(int num) {
int reversed = 0;
while(num != 0) {
int digit = num % 10;
reversed = reversed * 10 + digit;
num /= 10;
}
return reversed;
}

Conclusion

The whole function would then look like this:

public static int reverseDigits(int num) {
int reversed = 0;
while(num != 0) {
int digit = num % 10;
reversed = reversed * 10 + digit;
num /= 10;
}
return reversed;
}

This function takes an integer as input and returns its digits reversed as an integer.Number is updated in every iteration by removing the last digit.

Learn function in:

Reversing digits of a number

Swaps the order of digits within a given number

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Mathematical principle

The function works through the aspect of division and modulus calculation, which is fundamental in number theory. The modulus operation (`%`) retrieves the last digit of the number, while division (`/`) removes that last digit from the number in examination.

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