What is the difference between Go's map literals and map values?
In Go, a map is a collection of key-value pairs, where each key is unique and used to access its corresponding value. Map literals and map values are two ways of creating a map, but there are some differences between them.
A map literal is a compact way to create a map value. It is specified using the map keyword, followed by a list of key-value pairs enclosed in curly braces.
For example:
m := map[string]int{"one": 1, "two": 2, "three": 3}
Here, we have created a map with string keys and integer values. The keys "one", "two", and "three" map to the integer values 1, 2, and 3 respectively.
A map value, on the other hand, is created using the make function, which allocates and initializes a new map. For example:
m := make(map[string]int)
Here, we have created an empty map with string keys and integer values.
The main difference between map literals and map values is that map literals are a convenient way to create small maps with a fixed set of key-value pairs, whereas map values are more flexible and can be created and modified dynamically at runtime. Additionally, map literals can only be used to create new maps, while map values can be used to pass maps as arguments to functions, return maps from functions, and assign maps to variables.