Go case Study: built-in functions

This is a creation in Article, where the information may have evolved or changed.

Go pre-defines a few functions, which means you can use them without referencing any packages. All of the built-in functions are listed below (as of go1.1):

Closenew Paniccomplexdeletemakerecoverreallen Appendprintimagcap copyprintln

Note: You can use the godoc builtin command to get online documentation about built-in types and functions.

Close

for channel communication. Use it to close the channel.

Delete

used to delete an instance in a map.

Len and Cap

available for different types, Len is used to return string, slice, and array lengths.

New

used for various types of memory allocations.

Make

memory allocations for built-in types (map, slice, and channel).

Copy

used to replicate slice.

Append

used to append slice.

Panic and recover

used for exception handling mechanisms.

Print and println

is the underlying print function that can be used without the introduction of the FMT package. They are primarily used for debugging.

Complex, Real and imag

all for processing complex numbers. With the simple example given earlier, no further discussion of the plural is necessary.