swift-字符串的构造

let str1 = "text"
let str2 = "setting"
let str = str1 + str2
print(str)

var nunber:Int
nunber = 4
var url: String
url = "http://xiaosniygj.baon"
var message = "/dhiudha/.png"
message = "\(url)/dhiudha/\(nunber).png"
print(message)
![这里写图片描述](https://img-blog.csdn.net/20160424113221411)

//   字符串的比较
let str3 = "abfg"
//   判断为真会打印出，为假则不会打印
if str3 > "cdfg" {
print(str3)
}
let str4 = "456"
if str4 > "124" {
print(str4)
}
//   字符串hasSuffix，hasPrefix做后缀，前缀处理的，用判断字符串中是否包含这些字符
let str6 = "Hello"
if str6.hasSuffix("lo") {
print(str6)
}
//   小写转换
print(str6.lowercaseString)
//   大些转换
print(str6.localizedUppercaseString)