Create BigDecimal from String Value in Java

In this article, we will learn to create a BigDecimal from a string value in Java. The BigDecimal class in Java is highly versatile and often used for calculations requiring high precision, such as financial transactions or scientific computations. we'll explore two approaches to creating a BigDecimal from a string value, complete with examples.

When to Use BigDecimal

We can use the BigDecimal in the following conditions ?

• When working with financial calculations requiring precision (e.g., currency operations).
  
• When handling scientific computations involving large or highly precise numbers.
  
• When exact results are critical, rounding errors are unacceptable.

Using the BigDecimal Constructor

The simplest way to create a BigDecimal of BigDecimal class is by using its constructor and passing a string value as the parameter. This ensures that the value is represented accurately without any loss of precision.

Following are the steps to create a BigDecimal by using the constructor ?

• The BigDecimal object one is created using a string value "562537627.8787867".
  
• A second BigDecimal, two, is created using the BigDecimal.valueOf method for demonstration purposes.
  
• The two BigDecimal objects are added using the add method.
  
• The result is printed to the console, showcasing the high precision of BigDecimal.
  

Let us first create a BigDecimal type with string value ?

BigDecimal one = new BigDecimal("562537627.8787867");

Now, create a BigDecimal with long ?

BigDecimal two = BigDecimal.valueOf(562L);

After that use add() with the aug end value i.e. the value in "two" objects ?

one = one.add(two);

Example

Below is an example to create a BigDecimal by using the constructor ?

import java.math.BigDecimal;
public class Demo {
   public static void main(String[] argv) throws Exception {
      BigDecimal one = new BigDecimal("562537627.8787867");
      BigDecimal two = BigDecimal.valueOf(562L);
      one = one.add(two);
      System.out.println(one);
   }
}

Output

562538189.8787867

Using BigDecimal.valueOf

Another approach is using the BigDecimal.valueOf method. While this method is primarily used for converting primitive types like double or long to BigDecimal, it can be useful in certain scenarios where you're dealing with numeric values that do not require the use of a string constructor.

• The BigDecimal.valueOf method is used to create BigDecimal objects from a double or long value.
  

While BigDecimal.valueOf is useful, it might not always maintain precision if used with double. For exact values, prefer the string constructor.

Example

Below is an example of creating a BigDecimal by using the Valueof method?

import java.math.BigDecimal;
public class Demo {
   public static void main(String[] argv) throws Exception {
      // Creating a BigDecimal from a double value
      BigDecimal one = BigDecimal.valueOf(562537627.8787867);
      // Adding another BigDecimal from a long value
      BigDecimal two = BigDecimal.valueOf(562L);     
      // Performing addition
      one = one.add(two);
      // Displaying the result
      System.out.println(one);
   }
}

Output

562538189.8787867

Comparison Table

Aspect	BigDecimal Constructor	BigDecimal.valueOf
Input Type	Accepts a String as input.	Accepts double or long as input.
Precision	Maintains exact precision, as the input is treated as a string.	May lose precision when used with double due to floating-point representation.
Use Case	Ideal for high-precision calculations and large values.	Useful for straightforward conversions of primitive numeric values.
Recommended For	Applications needing high precision, such as financial or scientific computations.	General-purpose use when precision loss is not a concern.