Golang Map集合(5)

基本操作

var aMap map[string]string
fmt.Println(aMap == nil)     // true
//aMap["a11"] = "abc"        // 报错
//fmt.Println(aMap["a11"])
 
aMap = make(map[string]string)  // 创建一个map
fmt.Println(aMap == nil)        // false
 
aMap["a11"] = "abc"
fmt.Println(aMap["a11"])   // 输出"abc"
 
val, ok := aMap["a12"]
fmt.Println(val)  // val == "" 
fmt.Println(ok)   // false

直接赋值

aMap := map[string]string{
   "a11": "abc",
   "a12": "bbc",
   "a13": "cbc",
 }
 fmt.Println(aMap["a11"])

遍历

aMap["a11"] = "abc"
aMap["a12"] = "bbc"
aMap["a13"] = "cbc"
for key := range aMap {
  fmt.Println(key, aMap[key])
}
for key, val := range aMap {
  fmt.Println(key, val)
}
//a11 abc
//a12 bbc
//a13 cbc

删除元素

delete(aMap, "a11")  // 删除a11元素
delete(aMap, "b11")  // 不存在b11元素，不报错