Java MCQ: What is the size of a double data type in Java?
Answer:
Explanation:
In Java, the double data type is a primitive data type used for storing double-precision 64-bit IEEE 754 floating-point numbers. The size of a double in Java is 8 bytes, which equals 64 bits. This data type is primarily used for decimal values where a high degree of precision is required, such as scientific calculations, engineering simulations, and any other application where the accuracy of floating-point numbers is crucial.
The double data type provides a wider range and more precision than the float data type, which is only 32 bits (4 bytes). The 64-bit size allows it to represent very large or very small numbers with a significant degree of accuracy. For example, the double type can represent numbers as large as approximately 1.8e308 or as small as approximately 4.9e-324, with up to 15-16 decimal digits of precision. Here’s an example:
double price = 19.99;
System.out.println(price); // Outputs: 19.99
In this example, the double type is used to store a price value with decimal precision. This level of precision is often required in financial calculations where rounding errors could lead to significant inaccuracies. Because of its size and precision, double is commonly used for storing and manipulating numerical data that requires fractional values.
However, it’s important to note that using double for precise calculations, such as currency values, can sometimes lead to rounding errors due to the way floating-point numbers are represented in memory. For cases where absolute precision is necessary, the BigDecimal class is recommended. Nonetheless, for general-purpose calculations that involve floating-point arithmetic, double remains the preferred choice due to its balance between range, precision, and performance.
Reference links:
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