Contents

• Lists-切片

  • Python

  • Go

5. Lists-切片

切片是数组的一部分，其长度可以更改。

数组和切片之间的主要区别在于，使用数组需要预先知道大小。在Go中，无法平等地将值添加到现有切片中，因此，如果要轻松添加值，则可以以最大长度初始化切片并将其增量添加。

5.1. Python

#!/usr/bin/env python
# -*- coding:utf8 -*-
# auther; 18793
# Date：2020/4/21 13:50
# filename: sample1.py
# initialize list
numbers = [0] * 5
# change one of them
numbers[2] = 100
some_numbers = numbers[1:3]
print(some_numbers)  # [0, 100]
# length of it
print(len(numbers))  # 5

# initialize another
scores = []
scores.append(1.1)
scores[0] = 2.2
print(scores)  # [2.2]

5.2. Go

package main

import "fmt"

func main() {
    // initialized array
    var numbers [5] int // becomes [0, 0, 0, 0, 0]
    // change one of them
    numbers[2] = 100
    // create a new slice from an array
    some_numbers := numbers[1:3]
    fmt.Println(some_numbers) // [0, 100]
    // length of it
    fmt.Println(len(some_numbers)) //2

    // initialize a slice
    var scores []float64
    scores = append(scores, 1.1) // recreate to append
    scores[0] = 2.2              // change your mind
    fmt.Println(scores)          // prints [2.2]

    // when you don't know for sure how much you're going
    // to put in it, one way is to
    var things [100]string
    things[0] = "Perter"
    things[1] = "hujianli"
    fmt.Println(len(things))    //100

}