learn go language
xiaoxpai / awesomeproject Goto Github PK
View Code? Open in Web Editor NEWlearn go language
learn go language
解释 os.Args[1:]
s[m:n] 形式的切片表达式,产生从第 m 个元素到第 n-1 个元素的切片,下个例子用到的元素包含在 os.Args[1:len(os.Args)] 切片中。如果省略切片表达式的 m 或 n,会默认传入 0 或 len(s),因此前面的切片可以简写成 os.Args[1:]。
func main() {
fmt.Println(strings.Join(os.Args[1:], " "))
}
for by 2023年12月26日 shenzhen
上代码:
// Echo2 prints its command-line arguments.
package main
import (
"fmt"
"os"
)
func main() {
s, sep := "", ""
for _, arg := range os.Args[1:] {
s += sep + arg
sep = " "
}
fmt.Println(s)
}
空标识符说明
每次循环迭代,range 产生一对值;索引以及在该索引处的元素值。这个例子不需要索引,但 range 的语法要求,要处理元素,必须处理索引。一种思路是把索引赋值给一个临时变量(如 temp)然后忽略它的值,但 Go 语言不允许使用无用的局部变量(local variables),因为这会导致编译错误。
Go 语言中这种情况的解决方法是用 空标识符(blank identifier),即 _(也就是下划线)。空标识符可用于在任何语法需要变量名但程序逻辑不需要的时候(如:在循环里)丢弃不需要的循环索引,并保留元素值。大多数的 Go 程序员都会像上面这样使用 range 和 _ 写 echo 程序,因为隐式地而非显式地索引 os.Args,容易写对。
for by 2023年12月26日 shenzhen
A declarative, efficient, and flexible JavaScript library for building user interfaces.
🖖 Vue.js is a progressive, incrementally-adoptable JavaScript framework for building UI on the web.
TypeScript is a superset of JavaScript that compiles to clean JavaScript output.
An Open Source Machine Learning Framework for Everyone
The Web framework for perfectionists with deadlines.
A PHP framework for web artisans
Bring data to life with SVG, Canvas and HTML. 📊📈🎉
JavaScript (JS) is a lightweight interpreted programming language with first-class functions.
Some thing interesting about web. New door for the world.
A server is a program made to process requests and deliver data to clients.
Machine learning is a way of modeling and interpreting data that allows a piece of software to respond intelligently.
Some thing interesting about visualization, use data art
Some thing interesting about game, make everyone happy.
We are working to build community through open source technology. NB: members must have two-factor auth.
Open source projects and samples from Microsoft.
Google ❤️ Open Source for everyone.
Alibaba Open Source for everyone
Data-Driven Documents codes.
China tencent open source team.