Swift 字符串常用方法

//字符串的定义

var string = "Hello,swift";

let string1 = "hello,swift";

let string3 = "";

let string4 = string;

print(string);

print(string.uppercased());// 大写

print(string.lowercased());//小写

//字符串字节

let leng = string.lengthOfBytes(using: String.Encoding.utf8);

print(leng);

//获取字符串长度

let leng2 = string1.characters.count;

print(leng2,string3.characters.count,string4.characters.count);

//字符串遍历

for char in string1.characters{

print(char);

}

//字符串拼接

string += "liping";

print(string);

let str5 = string3 + string;

print("str5=",str5);

let str6 = [NSString .localizedStringWithFormat("%@,%@,%@","你好","开发","请善待")];

print(str6)

//追加字符

string.append("!")

print(string);

//字符串截取

let subStr = (string as NSString).substring(with: NSMakeRange(1, 6));

let subStr2 = (string as NSString).substring(from: 5);

let subStr3 = (string as NSString).substring(to: 5);

print("subStr=",subStr,"subStr2=",subStr2,"subStr3=",subStr3)

//字符串比较

let s1:NSString = "你好，swift"

let s2:NSString = "你好，李平";

if s1.isEqual(to: s2 as String) {

print("s1=s2");

}else{

print("s1!=s2");

}

//比较字符串的前缀后缀

let array = ["do.docx","good.docx","name.docx","data.json","good.json"];

for arrStr in array{

if arrStr.hasPrefix("good") {

print("前缀为good:\(arrStr)");

}

if arrStr.hasSuffix(".json") {

print("后缀为.json:\(arrStr)");

}

}

//字符串查找

let s3:NSString = "swift";

if (s1 as NSString).contains(s3 as String) {

print("s1里面存在s3");

}else{

print("不存在");

}

//数字化字符串

let s4 = "789";

print("数字化:\((s4 as NSString).intValue)");

详细代码查看：https://github.com/xiaolitou-ping/Swift-All