How to convert int to double in java

How to Convert from int to double in Java: Methods and Examples

Learn the three methods to convert from int to double in Java. This blog post provides code examples and discusses the advantages and disadvantages of each method.

• Using the assignment operator
• Typecasting from int to double
• Convert int to double in Java
• Using Double wrapper’s valueOf() method
• Converting from string to double in Java
• Converting from double to int in Java
• Other helpful code examples for converting from int to double in Java
• Conclusion
• How to convert from int to double in Java?
• Can Java automatically convert int to double?
• How to cast to a double in Java?
• How to convert int to float in Java?

If you’re a Java developer, you may have encountered a situation where you need to convert from int to double. Converting from one data type to another is a common task in programming, and understanding the different methods available to convert from int to double can be helpful in avoiding errors and improving the performance of your code. In this blog post, we will explore the three methods available to convert from int to double in Java, and provide code examples to illustrate each method.

Using the assignment operator

One of the simplest ways to convert from int to double in Java is to use the assignment operator. The assignment operator assigns the value of an expression to a variable. In this case, we can assign the value of an int variable to a double variable, and Java will automatically convert the value to a double.

int myInt = 5; double myDouble = myInt; 

In this example, we declare an int variable myInt with a value of 5, and then assign the value of myInt to a double variable myDouble . Java automatically converts the value of myInt to a double, and assigns the result to myDouble .

The advantages of using the assignment operator to convert from int to double are that it is simple and straightforward. However, the disadvantage of using this method is that it may result in a loss of precision, as int values are truncated when converted to double.

Typecasting from int to double

Another way to convert from int to double is to use typecasting. Typecasting is the process of converting one data type to another. In Java, we can use the cast operator (double) to convert an int to a double.

int myInt = 5; double myDouble = (double) myInt; 

In this example, we declare an int variable myInt with a value of 5, and then cast the value of myInt to a double using the cast operator. The result is assigned to a double variable myDouble .

The advantage of using typecasting to convert from int to double is that it is more precise than using the assignment operator. However, the disadvantage of using this method is that it may result in a loss of information if the int value is too large to be accurately represented as a double.

Convert int to double in Java

Using Double wrapper’s valueOf() method

The Double wrapper class is a class that is used to wrap the double primitive type in an object. It provides several methods that can be used to manipulate double values, including the valueOf() method, which can be used to convert an int to a double.

int myInt = 5; Double myDouble = Double.valueOf(myInt); 

In this example, we declare an int variable myInt with a value of 5, and then use the valueOf() method of the Double wrapper class to convert myInt to a Double object. The result is assigned to a Double variable myDouble .

The advantage of using the valueOf() method to convert from int to double is that it is more flexible than the other methods, as it allows you to manipulate the result as a Double object. However, the disadvantage of using this method is that it may be slower than the other methods, as it involves the creation of a new object.

Converting from string to double in Java

In addition to converting from int to double, you may also need to convert from string to double in Java. This is often required when reading input from the user or from a file. In Java, we can use the parseDouble() method of the Double class to convert a string to a double.

String myString = "3.14"; double myDouble = Double.parseDouble(myString); 

In this example, we declare a string variable myString with a value of “3.14”, and then use the parseDouble() method of the Double class to convert myString to a double. The result is assigned to a double variable myDouble .

The advantage of using the parseDouble() method to convert from string to double is that it is very flexible, as it can handle a wide range of input formats. However, the disadvantage of using this method is that it may throw an exception if the input string is not properly formatted.

Converting from double to int in Java

Finally, it is also possible to convert from double to int in java . This is often required when performing mathematical operations that require integer inputs. There are three methods available to convert from double to int in Java: typecasting, Math.round(), and Double.intValue().

Typecasting

As mentioned earlier, we can use typecasting to convert from double to int in Java.

double myDouble = 3.14; int myInt = (int) myDouble; 

In this example, we declare a double variable myDouble with a value of 3.14, and then cast the value of myDouble to an int using the cast operator. The result is assigned to an int variable myInt .

The advantage of using typecasting to convert from double to int is that it is simple and straightforward. However, the disadvantage of using this method is that it may result in a loss of precision, as double values are truncated when converted to int.

Math.round()

The Math.round() method can be used to round a double value to the nearest integer.

double myDouble = 3.14; int myInt = Math.round(myDouble); 

In this example, we declare a double variable myDouble with a value of 3.14, and then use the Math.round() method to round myDouble to the nearest integer. The result is assigned to an int variable myInt .

The advantage of using the Math.round() method to convert from double to int is that it provides a more accurate result than typecasting. However, the disadvantage of using this method is that it may be slower than typecasting.

Double.intValue()

The Double.intValue() method can be used to convert a Double object to an int.

Double myDouble = 3.14; int myInt = myDouble.intValue(); 

In this example, we declare a Double object myDouble with a value of 3.14, and then use the intValue() method to convert myDouble to an int. The result is assigned to an int variable myInt .

The advantage of using the Double.intValue() method to convert from double to int is that it allows you to manipulate the result as an Integer object. However, the disadvantage of using this method is that it may be slower than the other methods, as it involves the creation of a new object.

Other helpful code examples for converting from int to double in Java

In java, java int to double code example

// Primitive type int myInt = 5; double myDouble = (double)myInt; // explicit cast myDouble = myInt; // implicit cast // Object type Double myDouble = new Double(myInt) // via constructor myDouble = Double.valueOf(myInt) // via valueOf

Double d= new Double(i);//first way Double d2=Double.valueOf(i);//second way 

In java, how to change double to int in java code example

In java, int to double java code example

Conclusion

In this blog post, we have explored the different methods available to convert from int to double in Java, and provided code examples to illustrate each method. We have also discussed the methods available to convert from double to int in Java. By understanding these methods, you can improve the precision and performance of your Java code. Remember to choose the method that best suits your needs, and to test your code thoroughly to avoid errors. If you have any tips or experiences to share, please leave a comment below.

• Java Typecasting: A Beginner’s Guide (https://www.geeksforgeeks.org/ type-conversion-java -examples/)
• Java Conversions: int to double (https://www.programiz.com/java-programming/examples/int-to-double-conversion)
• Java Double Class (https://www.w3schools.com/java/java_ref_double.asp)

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How to Convert int to double in Java

In Java, the most popular primitive data types are “double” and “int“. The double data type is more extensive than the int type because it stores 64-bit floating-point numbers and takes more memory space, whereas the integer type stores 32-bit integers. Java implicitly converts int values to double. However, you may need to perform this int to double conversion explicitly.

This blog will describe the method for converting int to double in Java.

How to Convert int to double in Java?

For converting int to double, you can use the:

We will now check out each of the mentioned methods one by one.

Method 1: Convert int to double Using Assignment Operator

In Java programming language, the lower data type can be easily converted to the higher data type using the Assignment operator “=”. This is called an implicit conversion.

Here, the assignment operator “=” will convert “a” int type variable to “b”, which is a double type variable.

Example
In this example, firstly, we will create an int variable named “a” with the following value:

Then, we will convert it to double using the “=” assignment operator and store the resultant value in “b”:

Lastly, execute the “System.out.println()” method to display the converted value on the console:

The output shows that the integer is successfully converted into a double value:

Method 2: Convert int to double Using Typecasting

Typecasting is used when we want to convert one datatype to another. More specifically, it can also be utilized for int to double conversion.

Here, we will convert “a” int type variable to “b”, which is a double type variable. The (double) indicates the required typecasted data type.

Example
In this example, we will use the same integer type “a” variable and convert its value to “double” using Typecasting. Here, the assignment operator is also used; however, the specified integer is typecasted in the double and then stored in the double type variable “b”:

Then, print out the converted value using the “System.out.println()” method:

Want to utilize any built-in Java method for the specified purpose? Head toward the next section!

Method 3: Convert int to double Using valueOf() Method

The “Double” Java wrapper class offers a “valueOf()” method that can be used to convert int to double. It is a static type method, which means we do not need to create an object and call the method by using the class name, as it can be accessed without this additional step.

Here, we will convert “a” int type variable to “b” by passing it as an argument to the “valueOf()” method.

Example
Here, we will convert the value of the already created “a” variable using the valueOf() method. The method will take “a” as an argument and returns the converted double value:

Finally, print out the converted value using the “System.out.println()” method:

We compiled all the essential instructions related to converting int to double in Java.

Conclusion

To convert int to double in Java, there are three methods: using the Assignment operator, using Typecasting, and the valueOf() method of the Double Java wrapper class. All these methods approximately work the same; however, you may choose any one depending on your preferences. In this post, we described the methods to convert an int to double in Java.

About the author

Farah Batool

I completed my master’s degree in computer science. I am an academic researcher and love to learn and write about new technologies. I am passionate about writing and sharing my experience with the world.

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