What is the difference between float and double in c++

The difference between float (32 bits) and double (64 bits) is: different precision. The effective number of double is 2 times that of float. The range is different. The range of double is larger than float. The usage is different. Float is used for low precision requirements. , double is used for high-precision calculations, the storage space is different, float occupies 4 bytes, double occupies 8 bytes, the performance is different, float operation speed is faster

The difference between float and double in C

float and double are two floating-point data types in C, used to represent decimals or real numbers. Their main differences are:

1. Precision

• float: Single-precision floating point number, stored using 32 bits (4 bytes), with approximately 6 -7 significant digits (number of digits after the decimal point).
• double: Double precision floating point number, stored using 64 bits (8 bytes), with approximately 15-16 significant digits.

2. Range

• float: The representable range is from -3.4028235e 38 to 3.4028235e 38.
• double: The representable range is from -1.7976931348623157e 308 to 1.7976931348623157e 308.

3. Usage

• float: Usually used in situations where accuracy is not high, such as graphics, games, etc.
• double: used in situations where higher precision calculations are required, such as science, engineering and other fields.

4. Storage space

• float: occupies 4 bytes of storage space.
• double: occupies 8 bytes of storage space.

5. Performance

• float: Floating point operations are faster due to lower precision.
• double: higher precision, slightly slower floating point operation.

Other notes:

• Default to float: If no suffix is ​​specified after a number, the compiler will interpret it as float by default.
• You can use suffixes to specify the type: you can use the f or F suffix to specify float, and use the d or D suffix to specify double.
• Type conversion: You can use the cast operator (static_cast) to convert between float and double.

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