Double in Java is a keyword used to declare double-precision floating-point numbers, with a large range (±(21023-1)x 2-1022 to ±(21023-1)x 21023) and high precision ( 15-17 significant figures) and takes up 8 bytes of storage space. Compared with float, double has a larger range and higher precision, but also has larger storage space.
What is double in Java
In Java programming language, double
is A keyword used to declare and use double-precision floating-point types. Double-precision floating point numbers are a data type used to represent numbers with a larger range and precision. They are generally used for scientific calculations or processing high-precision values.
Characteristics of double-precision floating-point numbers
Using double
To declare a double type variable, you can use the following syntax:
<code class="java">double variableName;</code>
For example:
<code class="java">double myDouble = 3.14159265358979323846;</code>
<code class="java">double myDouble = 1.234e10; // 科学计数法表示法</code>
Comparison with other floating point types
There are other floating point types in Java, such as float
. Compared to double
, float
has smaller range and precision, but takes up less storage space. The following is a comparison of different floating point types:
Floating point type | Range | Precision | Storage space |
---|---|---|---|
±(2 | 1023-1)x 2-1022 to±( 21023-1) x 21023 | 15-17 bits8 bytes | |
±(2 | 127-1)x 2-126 to±(2127-1)x 2128 | 6-7 bits4 bytes |
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