In Java, "conversion" means changing the type of data from one form to another. This is often necessary when working with different kinds of data or when you want to perform operations with data of different types.
Java provides two primary types of conversions:
Implicit
Explicit.
Implicit Conversion: Automatic and Safe
Implicit conversion, also known as widening or automatic type conversion, is when Java automatically changes a smaller data type into a larger one without you having to do anything.
It's safe because it doesn't result in data loss.
Example of Implicit Conversion,
int smallNumber = 5;
double bigNumber = smallNumber; // Implicit conversion from int to double
Here, smallNumber (an integer) is automatically converted to bigNumber (a double) because a double can hold larger values.
2. Explicit Conversion (Casting): Manual and Careful
Explicit conversion, also known as casting, is when you manually change a larger data type into a smaller one. It's manual because you need to specify the conversion, and it can be risky because it might cause data loss or unexpected results.
Example of Explicit Conversion:
double bigNumber = 7.9;
int smallNumber = (int) bigNumber; // Explicit conversion from double to int (data loss may occur)
In this example, you manually cast bigNumber (a double) to an int. This might lead to data loss because integers cannot represent decimal fractions like 7.9.
3. String Conversion: Converting to and from Text
Another common type of conversion in Java is converting data to and from text (strings). This is useful for reading and displaying data.
Example of String Conversion,
String textNumber = "42";
int numericValue = Integer.parseInt(textNumber); // Convert string to int
In this example, we convert the string "42" to an integer, allowing us to perform numeric operations.
In Java, conversion is all about changing data from one type to another. Implicit conversion is automatic and safe, while explicit conversion (casting) is manual and potentially risky. String conversion is essential for working with text data. Understanding and using these conversion techniques correctly is crucial for effective Java programming.
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