How To Round To The Nearest Hundredth In Java

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In this article, I will guide you on how to round to the nearest hundredth in Java. As an experienced Java developer, I have frequently encountered situations where precise rounding is necessary, especially when dealing with financial calculations or other applications that require accuracy.

Firstly, let’s understand the concept of rounding to the nearest hundredth. When rounding to the nearest hundredth, we are aiming to get a result that has a maximum of two decimal places. For example, if we have a number like 3.456, rounding to the nearest hundredth would give us 3.46.

To achieve this in Java, we can make use of the built-in Math.round() function. However, keep in mind that this function rounds to the nearest whole number, not to a specific decimal place. Therefore, we need to perform some additional steps to accomplish our goal.

Step 1: Multiply the Number

The first step is to multiply the number by 100. This will move the decimal two places to the right. For example, if we have the number 3.456, multiplying it by 100 gives us 345.6.

Step 2: Round to the Nearest Whole Number

Next, we use the Math.round() function to round the multiplied number to the nearest whole number. For instance, if we have 345.6, rounding it gives us 346.

Step 3: Divide by 100

Finally, we divide the rounded number by 100 to move the decimal point two places back to the left. For example, if we have 346, dividing it by 100 gives us 3.46.

Let’s put it all together now:

// Multiplied by 100
double multiplied = number * 100;

// Rounded to the nearest whole number
long rounded = Math.round(multiplied);

// Divided by 100
double result = rounded / 100.0;

You can incorporate this code into your Java program to round any number to the nearest hundredth. Make sure to replace number with the variable or value you want to round.

Now, let’s explore a practical example using this rounding technique:

double price = 19.99;
double discountedPrice = price * 0.8; // Apply a 20% discount

double roundedPrice = Math.round(discountedPrice * 100) / 100.0;

System.out.println("The discounted price is: $" + roundedPrice);

In this example, we calculate a discounted price and round it to the nearest hundredth using the rounding technique we discussed earlier.

Conclusion

Rounding to the nearest hundredth in Java can be achieved by multiplying the number by 100, rounding it to the nearest whole number, and dividing it by 100. By following these steps, you can ensure accurate rounding of decimal values to the desired precision. Remember to use this technique whenever you need precise rounding in your Java applications.