Map Declaration and Initialization

We can declare an empty map using the make() function. Below is the syntax we need to follow:

Here, mapName is the name of the map, keyType is the expected type of the keys, and valueType is the expected type of the values. The term map is a keyword.

We can declare a map called courseData with keys of type string and values of type int.

index


              1
            
var courseData = make(map[string]int)

If we attempt to output this map, we will receive an output indicating an empty map:

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              1
            
fmt.Println(courseData) // Output: map[]

We can initialize a map with some data using the following syntax:

Note

You can place or omit spaces in the map declaration syntax; therefore, both map[keyType]valueType and map [keyType] valueType are valid.

Using the above syntax, we can create a map that has some initial data in it:

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              1234567
            
myMap := map[string]int {
	"a": 10,
	"b": 11,
	"c": 12,
}

fmt.Println(myMap) // Output: map[a:10 b:11 c:12]

Everything was clear?

Thanks for your feedback!

Section 6. Chapter 5