Convert Float to String in Java

(Last Updated On: 05/02/2024)

In Java, converting float to string is a common task with various methods available. Understanding these methods is crucial for precision, formatting, and performance. In this blog explores multiple conversion techniques, including String.valueOf(), Float.toString(), DecimalFormat, and StringBuilder/StringBuffer, offering insights into their usage and suitability for different scenarios.

How to Convert Float to String in Java?

There are many methods to Convert Float to String, a few of which we will cover in this blog.

A. Convert Float to String by Using String.valueOf() method

This method converts the specified `float` value to its string representation using the `valueOf` static method of the `String` class.

// Convert Float to String in Java
public class covertFloatToStringEx {
    public static String
    convertFloatToString(float floatValue)
    {
   	 return String.valueOf(floatValue);
    }

    // Driver code
    public static void main(String[] args)
    {

   	 // The float value
   	 float floatValue = 65.5f;

   	 // The expected string value
   	 String stringValue;

   	 // Convert float to string
   	 stringValue = convertFloatToString(floatValue);

   	 // Print the expected string value
   	 System.out.println(
   		 floatValue
   		 + " after converting into string = "
   		 + stringValue);
    }
}

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Output:

65.5 after converting into string = 65.5

Explain of the Code:

1. Class Declaration- Declares a class named `covertFloatToStringEx`.

2. Method Declaration- convertFloatToString: Defines a static method `convertFloatToString` that takes a `float` parameter named `floatValue`.

   – Inside the method, it converts the `float` value to its string representation using `String.valueOf(floatValue)` and returns the result.

3. Main Method- Begins the main method where the execution of the program starts.

4. Variable Declarations- Declares a `float` variable `floatValue` and initializes it with the value `65.5` and also Declares a `String` variable `stringValue`.

5. Convert Float to String- Calls the `convertFloatToString` method to convert the `floatValue` to a `String` and assigns the result to `stringValue`.

6. Print Result- Prints the original `float` value (`floatValue`) concatenated with a descriptive message and the converted `String` value (`stringValue`) to the console.

B. Using Float.toString() method

This static method of the `Float` class converts the specified `float` value to its string representation.

// Java Program to convert float to String value
import java.util.*;
public class covertFloatToStringEx {
    // Function to convert float value to String value
    public static String
    convertFloatToString(float floatValue)
    {
   	 // Convert float value to String value
   	 // using valueOf() method
   	 return Float.toString(floatValue);
    }

    // Driver code
    public static void main(String[] args)
    {

   	 // The float value
   	 float floatValue = 87.6f;

   	 // The expected string value
   	 String stringValue;

   	 // Convert float to string
   	 stringValue = convertFloatToString(floatValue);

   	 // Print the expected string value
   	 System.out.println(
   		 floatValue
   		 + " after converting into string = "
   		 + stringValue);
    }
}

Output:

87.6 after converting into string = 87.6

Explanation of the Code:
1. Import Statement: Imports the `java.util` package, although it’s not used in the code. It’s unnecessary in this example.

2. Class Declaration: Declares a class named `covertFloatToStringEx`.

3. Method Declaration – convertFloatToString: Defines a static method `convertFloatToString` that takes a `float` parameter named `floatValue`.Inside the method, it converts the `float` value to its string representation using `Float.toString(floatValue)` and returns the result.

4.Main Method: Begins the main method where the execution of the program starts.

5. Variable Declarations: Declares a `float` variable `floatValue` and initializes it with the value `87.6`.Declares a `String` variable `stringValue`.

6. Convert Float to String: Calls the `convertFloatToString` method to convert the `floatValue` to a `String` and assigns the result to `stringValue`.

7. Print Result: Prints the original `float` value (`floatValue`) concatenated with a descriptive message and the converted `String` value (`stringValue`) to the console.

That’s how to Convert Float to String in Java using the `Float.toString(float)` method.

C. Using DecimalFormat class

This method formats the specified `float` value using a `DecimalFormat` object, which allows for more complex formatting options and returns the resulting string.

import java.text.DecimalFormat;

public class FloatToStringEx {
	// Driver code
	public static void main(String[] args) {
    	float decimalFloat = 98.457f;
    	DecimalFormat decimalFormat = new DecimalFormat("#.##"); // Pattern for two decimal places
    	String formattedString = decimalFormat.format(decimalFloat);
    	System.out.println("Formatted string using DecimalFormat: " + formattedString);
	}
}

Output:

Formatted string using DecimalFormat: 98.46

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Explanation of the Code:

1. Import Statement: The code imports the `DecimalFormat` class from the `java.text` package. This class is used for formatting decimal numbers.

2. Class Declaration: It declares a class named `FloatToStringEx`.

3. Main Method: The program starts execution from the `main` method.

4. Variable Declaration – decimalFloat: It declares a `float` variable named `decimalFloat` and initializes it with the value `98.457`.

5. DecimalFormat Initialization: The code creates a new `DecimalFormat` object named `decimalFormat` with a formatting pattern `”#.##”`, specifying two decimal places.

6. Format Float to String: The `format()` method of the `DecimalFormat` object is used to format the `decimalFloat` value according to the specified pattern. The resulting formatted string is stored in the variable `formattedString`.7. Print Result: A message indicating that the formatted string is generated using `DecimalFormat` is printed to the console, followed by the formatted string itself.

Dealing With Code

Whenever you’re writing there may be an error you should know how to handle.Along with that tips and tricks to effectively implementation of code.

Error Handling:

1. Input Validation: Validate input values to ensure they are within acceptable ranges before performing conversions.

2. Exception Handling: Wrap conversion code in try-catch blocks to handle exceptions gracefully, especially for scenarios like invalid input or unexpected errors during conversion.

3. Logging: Use logging frameworks like Log4j to log errors and debug information for troubleshooting purposes.

Tips and Tricks:

1. Choosing the Right Method: Discuss the pros and cons of each conversion method and suggest the most suitable method based on factors like precision requirements, performance, and formatting flexibility.

2. Performance Optimization: Provide tips for optimizing performance, such as reusing DecimalFormat instances or using StringBuilder/StringBuffer for concatenating strings efficiently.

3. Localization: Mention considerations for localization when formatting numbers, such as using Locale-specific formatting patterns.

In conclusion, understanding the various methods to convert float to string in Java is essential for precision, formatting, and performance. By exploring techniques like String.valueOf(), Float.toString(), DecimalFormat, and more, developers can choose the most suitable approach for their specific requirements, ensuring robust and efficient code.

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FAQs for Convert Float to String in Java

What are the common methods to convert float to string in Java?

Common methods include String.valueOf(), Float.toString(), and using DecimalFormat for custom formatting.

Which method should I use for converting a float to a string?

It depends on your specific requirements. Use String.valueOf() for general-purpose conversions, Float.toString() for simplicity, and DecimalFormat for custom formatting options.

Are there any performance differences between these methods?

Float.toString() may have slightly better performance compared to String.valueOf() due to its direct conversion approach.

Can I specify formatting options when converting a float to a string?

Yes, you can use DecimalFormat to specify formatting options such as the number of decimal places or scientific notation.

Are there any considerations for handling edge cases when converting float to string?

Yes, be mindful of precision loss and rounding errors, especially when dealing with large or very small float values. Additionally, handle special cases such as NaN or infinity appropriately.

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