Go Language Learning Road four: Dictionaries

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

Associative array: (hash or dictionary)

Map is the go built-in correlation data type, the dictionary is accessed by Key to Value , the access format is as follows:

Value=mapname[key]

In fact, the array can be regarded as a dictionary of key-value type integer, which can be said that the array is a special dictionary.

1. Dictionary Item Lookup

To find a specific key-value pair from the dictionary, you can:

V,ok:=mapname[key]

After executing this statement, if the key value of the lookup exists, assign the value of the key corresponding to v, OK to be true , conversely, v equals 0 , OK bit false . Test Case:

var map1 = map[string]int{"Key1": +, "Key2": 200}

v,ok:=map1["Key1"]

If ok{

Fmt. Println (V,ok)

}else{

Fmt,println (v)

}

2. Deletion and addition of dictionaries

The code example is shown below:

var map1 = map[string]int{"Key1": 1, "Key2": 2, "Key3": 3}

For k, V: = Range Map1 {

Fmt. Println (k, v)

if k = = "Key1" {

Delete (Map1, k)

}

if k = = "Key3" {

map1["Key2"] = 5

}

}

Fmt. Println (MAP1)

Operation Result:

Key1 1

Key2 2

Key3 3

Map[key3:3 Key2:5]

The dictionary is relatively simple, do not spend too much ink to repeat the