1、函数返回值

package main

import "fmt"

var num int = 10;
var rslt1, rslt2 int;
var rslt3, rslt4 int;

func main() {
    rslt1, rslt2 = getX2AndX3_1(num);
    fmt.Printf("num = %d, 2x num = %d, 3x num = %d\n", num, rslt1, rslt2)
    rslt3, rslt4 = getX2AndX3_2(num);
    fmt.Printf("num = %d, 2x num = %d, 3x num = %d\n", num, rslt3, rslt4)
}

func getX2AndX3_1(input int) (int, int) {
    return 2 * input, 3 * input;
}

/**
  * 这种方式尽量避免使用，代码可读性差
  */
func getX2AndX3_2(input int) (rslt3 int, rslt4 int) {
    rslt3 = 2 * input;
    rslt4 = 3 * input;
    return
}

2、递归

package main

import "fmt"

var num int = 10;
var rslt1, rslt2 int;
var rslt3, rslt4 int;

func main() {
    
    for i := 0; i < 10; i++ {
        result := fibonacci(i);
        fmt.Printf("fibonacci(%d) is: %d\n", i, result);
    }
}

func fibonacci(n int) int {
    res := 0;
    if(n <= 1) {
        res = 1;
    } else {
        res = fibonacci(n-1) + fibonacci(n-2);
    }
    return res;
}

3、闭包

package main

import "fmt"

func main() {
    funcAddBmp := MakeAddSuffix(".bmp");
    funcAddJpg := MakeAddSuffix(".jpg");

    fmt.Println("filename with bmp is ", funcAddBmp("rantu"));
    fmt.Println("filename whth jpg is ", funcAddJpg("9app"));
}

func MakeAddSuffix(suffix string) func(string) string {
    return func(name string) string {
        return name + suffix;
    }
}

5、 利用缓存实现fibonacci数列

package main

import "fmt"
import "time"

const LIMIT = 41;
var fibs [LIMIT]uint64;

func main() {
    var result uint64 = 0
    start := time.Now();
    for i := 0; i < LIMIT; i++ {
        result = fibonacci(i);
        fmt.Printf("fibonacci(%d) is: %d\n", i, result)
    }
    end := time.Now();
    durtion := end.Sub(start);
    fmt.Println("cost time :", durtion);
}

func fibonacci(n int) uint64 {
    var res uint64;
    if fibs[n] != 0 {
        return fibs[n];
    }
    if(n <= 1) {
        res = 1;
    } else {
        res = fibonacci(n-1) + fibonacci(n-2);
    }
    fibs[n] = res;
    return res;
}