Swift_字符串的基本使用

字符串基本使用:

1. 定义字符串变量

var string = "hello"```

#####2. 创建空字符串变量(两者等价)

var string1 = ""
var string2 = String()```

3. 判断空字符串 , 通过 .isEmpty 方法

if(string1.isEmpty){
    
    print("String is empty")
    
}```

#####4. 字符串拼接 += 方法

var string3 = "http://"
string3 += "www.baidu.com"
print(string3)```

5. 获取字符串长度

let length = string3.characters.count
print("length = ", length)

6. 字符串比较

let name1 = "abc"
let name2 = "def"
if(name1 == name2){
    
    print("\(name1) equals \(name2)")
}else{
    
    print("不同")
    print("\(name1) equals \(name2)")
    print(name1, "equals", name2)
}```

#####7. 插值

let num = 3.0
let newNum = "(num) * 2.5 = (num * 2.5)"
print(newNum)
print(num ,"* 2.5 = ", num * 2.5)```

插值运行结果.png