golang之map数据类型
package mainimport
"fmt"
func testMap() {
//两种声明map方式，切记，必须初始化才能用，否则panic
//var a mapstring = mapstring{// "key": "value",//} a := make(mapstring, 10)
a["abc"] = "efg"
//map的key是唯一的，修改值可以直接改
a["abc"] = "efg2"
a["abc1"] = "efg"
fmt.Println(a)
}
//map嵌套map
//map是无序排序
func testMap2() {
a := make(mapmapstring, 100)
a["key1"] = make(mapstring)
a["key1"]["key2"] = "abc"
a["key1"]["key3"] = "abc"
a["key1"]["key4"] = "abc"
a["key1"]["key5"] = "abc"
fmt.Println(a)
}
func modify(a mapmapstring) {
_, ok := a["zhangsan"]
if !ok {
a["zhangsan"] = make(mapstring)
}
//与_,ok写法一样
//if a["zhangsan"] == nil {}
//
a["zhangsan"]["passwd"] = "123456"
a["zhangsan"]["nickname"] = "pangpang"
return
}
func testMap3() {
a := make(mapmapstring, 100)
modify(a)
fmt.Println(a)
}
func trans(a mapmapstring) {
for k, v := range a {
fmt.Println(k)
for k1, v1 := range v {
fmt.Println("\t", k1, v1)
}
}
}
func testMap4() {
a := make(mapmapstring, 100)
a["key1"] = make(mapstring)
a["key1"]["key2"] = "abc"
a["key1"]["key3"] = "abc"
a["key1"]["key4"] = "abc"
a["key1"]["key5"] = "abc"
//删除map键的内置函数delete
//delete(a,"key1")
trans(a)
fmt.Println(len(a))
}
func testMap5() {
var a []mapint
a = make([]mapint, 5)
//for i:=0;i
页:
[1]