In C language, for example `6.18f`, this is a floating point constant.
`6.18` is a floating point number, and the suffix `f` indicates that the floating point number is a single precision floating point number.
In C language, the default floating-point constant type is double-precision floating-point number. If you want to use single-precision floating-point number, you can add `f` or `F` suffix after the constant .
For example, `6.18f` represents a single-precision floating point number, while `6.18` represents a double-precision floating point number. The two occupy different spaces in memory. Single-precision floating-point numbers usually occupy 4 bytes, while double-precision floating-point numbers usually occupy 8 bytes.
Using single-precision floating point numbers saves memory space, but you may lose precision because single-precision floating point numbers have fewer significant digits. When choosing to use single precision or double precision, you need to decide based on specific needs and accuracy requirements.