标准库的字符串包提供了许多有用的字符串相关函数。这里有一些例子就像使用一个包的感觉。
将fmt.println
别名缩写为一个较短的名称,因为将在下面示例代码中使用它。
下面是字符串中可用函数的示例。因为这些是来自包的函数,而不是字符串对象本身的方法,所以我们需要将有问题的字符串作为函数的第一个参数传递。可以在字符串包docs
中找到更多的函数。
不是字符串的一部分,但值得一提的是,以字节为单位获取字符串长度并按索引获取字节的机制。
注意len
和索引在字节级上工作的。 go使用utf-8
编码字符串,因此这通常是有用的。如果使用潜在的多字节字符,将需要使用编码转换操作。有关详细信息,请参阅go中的字符串,字节,符文和字符(http://blog.golang.org/strings)。
所有的示例代码,都放在
f:\worksp\golang
目录下。安装go编程环境请参考:http://www.h3.com/go/go_environment.html
string-functions.go
的完整代码如下所示 -
package main
import s "strings"
import "fmt"
// we alias `fmt.println` to a shorter name as we'll use
// it a lot below.
var p = fmt.println
func main() {
// here's a sample of the functions available in
// `strings`. since these are functions from the
// package, not methods on the string object itself,
// we need pass the string in question as the first
// argument to the function. you can find more
// functions in the [`strings`](http://golang.org/pkg/strings/)
// package docs.
p("contains: ", s.contains("test", "es"))
p("count: ", s.count("test", "t"))
p("hasprefix: ", s.hasprefix("test", "te"))
p("hassuffix: ", s.hassuffix("test", "st"))
p("index: ", s.index("test", "e"))
p("join: ", s.join([]string{"a", "b"}, "-"))
p("repeat: ", s.repeat("a", 5))
p("replace: ", s.replace("foo", "o", "0", -1))
p("replace: ", s.replace("foo", "o", "0", 1))
p("split: ", s.split("a-b-c-d-e", "-"))
p("tolower: ", s.tolower("test"))
p("toupper: ", s.toupper("test"))
p()
// not part of `strings`, but worth mentioning here, are
// the mechanisms for getting the length of a string in
// bytes and getting a byte by index.
p("len: ", len("hello"))
p("char:", "hello"[1])
}
// note that `len` and indexing above work at the byte level.
// go uses utf-8 encoded strings, so this is often useful
// as-is. if you're working with potentially multi-byte
// characters you'll want to use encoding-aware operations.
// see [strings, bytes, runes and characters in go](http://blog.golang.org/strings)
// for more information.
执行上面代码,将得到以下输出结果 -
f:\worksp\golang>go run string-functions.go
contains: true
count: 2
hasprefix: true
hassuffix: true
index: 1
join: a-b
repeat: aaaaa
replace: f00
replace: f0o
split: [a b c d e]
tolower: test
toupper: test
len: 5
char: 101