Swift学习 字符串的操作

1、字符串的拼接

字符串的拼接用 “＋”

   let str1 = "Hello"   let str2 = "World"   let str3 = str1 + str2   print(str3);

输出：HelloWorld

2、字符串的插入

字符串的插入用 “\( )”

    for var i = 0; i<3; i++ {    print("index is \(i)")

输出：
index is 0
index is 1
index is 2

3、字符串的遍历

    let str = "This is a sting"    for character in str.characters {        print(character)    }

4、字符串的长度

    let str = "This is a sting"    let num = str.characters.count;    print(num)

输出：15

5、字符串的判断

    //判断是否相等    let str1 = "This is a sting"    let str2 = "This"    print(str1 == str2)    //判断是否包含前缀    print(str1.hasPrefix(str2))    //判断是否包含后缀    print(str1.hasSuffix(str2))

6、字符串分割成数组

    let date = "2016-03-10"    let arr = date.componentsSeparatedByString("-");    for str in arr {        print(str)    }