Java String To Float Examples

绝地灬酷狼 2023-10-18 20:24 21阅读 0赞

### [Java String To Float Examples][] ###

Feb 21, 2015 [Core Java][], [Examples][], [Snippet][] comments

This tutorial will show example codes on how to convert **Java String To Float**. Performing conversion from String to float is a common scenario when programming with Core Java.

Here are some quick reference example codes:

*  [Convert using Float.parseFloat()][Convert using Float.parseFloat]
 *  [Convert using Float.valueOf()][Convert using Float.valueOf]
 *  [Convert using new Float(String).floatValue()][Convert using new Float_String_.floatValue]
 *  [Convert using DecimalFormat][]

#### Convert using Float.parseFloat() ####

The Float.parseFloat() static method parses the string argument and returns a float value.

**Syntax**

public static float parseFloat(String s) throws NumberFormatException

The parameter *s* will be converted to a primitive float value. Note that the method will throw a NumberFormatException if the parameter is not a valid float.

**Example**

String numberAsString = "153.25";
    float number = Float.parseFloat(numberAsString);
    System.out.println("The number is: " + number);

When you run the code above, the output will show this:

The number is: 153.25

This is the most common and popular solution when you need to convert a String to float. Note that the resulting value is not an instance of the Float class but just a plain primitive float value.

#### Convert using Float.valueOf() ####

The Float.valueOf() static method will return a Float object holding the value of the specified String.

**Syntax**

public static Float valueOf(String s) throws NumberFormatException

Note that the method will throw a NumberFormatException if the parameter is not a valid float.

String numberAsString = "153.25";
    float number = Float.valueOf(numberAsString);
    System.out.println("The number is: " + number);

This will output:

The number is: 153.25

This is the most common method when you wish to convert a String to Float. Note that the resulting value is an instance of the Float class and not a primitive float value.

#### Convert using new Float(String).floatValue() ####

Another alternative method is to create an instance of Float class and then invoke it's floatValue() method.

**Example**

String numberAsString = "153.25";
    Float floatObject = new Float(numberAsString);
    float number = floatObject.floatValue();

We can shorten to:

String numberAsString = "153.25";
    float number = new Float(numberAsString).floatValue();

or just:

float number = new Float("153.25").floatValue();

#### Convert using DecimalFormat ####

The class **java.text.DecimalFormat** is a class that can be used to convert a number to it's String representation. It can also be used the other way around - it can parse a String into it's numerical representation.  
**Example**

String numberAsString = "153.25";
    DecimalFormat decimalFormat = new DecimalFormat("#");
    try {
       float number = decimalFormat.parse(numberAsString).floatValue();
       System.out.println("The number is: " + number);
    } catch (ParseException e) {
       System.out.println(numberAsString + " is not a valid number.");
    }

Will output

The number is: 153.25

Note that the *parse()* method will throw a ParseException when there are problems encountered with the String.

[Java String To Float Examples]: http://javadevnotes.com/java-string-to-float-examples
[Core Java]: http://javadevnotes.com/category/core-java
[Examples]: http://javadevnotes.com/category/examples
[Snippet]: http://javadevnotes.com/category/snippet
[Convert using Float.parseFloat]: http://javadevnotes.com/java-string-to-float-examples/#p1
[Convert using Float.valueOf]: http://javadevnotes.com/java-string-to-float-examples/#p2
[Convert using new Float_String_.floatValue]: http://javadevnotes.com/java-string-to-float-examples/#p3
[Convert using DecimalFormat]: http://javadevnotes.com/java-string-to-float-examples/#p4