GO语言基础语法2 | 青训营笔记

6.map

package main

import (
	"fmt"
)

func main() {
	m := make(map[string]int)
	m["one"] = 1
	m["two"] = 2
	fmt.Println(m)
	fmt.Println(len(m))
	fmt.Println(m["one"])
	fmt.Println(m["unknown"])

	r, ok := m["unknown"]
	fmt.Println(r, ok)

	delete(m, "one")

	m2 := map[string]int{"one": 1, "two": 2}
	var m3 = map[string]int{"one": 1, "two": 2}
	fmt.Println(m2, m3)
}

7.range

package main

import (
	"fmt"
)

func main() {
	nums := []int{2, 3, 4}
	sum := 0
	for i, num := range nums {
		sum += num
		if num == 2 {
			fmt.Println("index:", i, ",num:", num)
		}
	}
	fmt.Println(sum)

	m := map[string]string{"a": "A", "b": "B", "c": "C"}
	for k, v := range m {
		fmt.Println(k, v)
	}
	for k := range m {
		fmt.Println("key", k)
	}
}