在Swift中追加String

Question

我是iOS新手.我目前正在使用Objective-C和Swift学习iOS.

要在Objective-C中附加一个字符串,我使用以下代码:

 NSString *string1 = @"This is";
 NSString *string2 = @"Swift Language";
 NSString *appendString=[NSString stringWithFormat:@"%@ %@",string1,string2];
 NSLog(@"APPEND STRING:%@",appendString);

有人请指导我.

Answer 1

它非常简单:

对于ObjC:

     NSString *string1 = @"This is";
     NSString *string2 = @"Swift Language";

ForSwift:

    let string1 = "This is"
    let string2 = "Swift Language"

对于ObjC AppendString:

     NSString *appendString=[NSString stringWithFormat:@"%@ %@",string1,string2];

对于Swift AppendString:

    var appendString1 = "\(string1) \(string2)"
    var appendString2 = string1+string2

结果:

    print("APPEND STRING 1:\(appendString1)")
    print("APPEND STRING 2:\(appendString2)")

Swift中的完整代码:

    let string1 = "This is"
    let string2 = "Swift Language"
    var appendString = "\(string1) \(string2)"
    var appendString1 = string1+string2
    print("APPEND STRING1:\(appendString1)")
    print("APPEND STRING2:\(appendString2)")

Answer 2

在Swift中,追加字符串就像:

let stringA = "this is a string"
let stringB = "this is also a string"
let stringC = stringA + stringB

或者您可以使用字符串插值.

let stringC = "\(stringA) \(stringB)"

请注意,它们之间现在会有空格.

注意:我看到其他答案正在使用var很多.字符串不会改变,因此应使用声明let.我知道这是一个小练习,但养成最佳实践的习惯是很好的.特别是因为这是Swift的一大特色.

Answer 3

let string2 = " there"
var instruction = "look over"

选择1:

 instruction += string2;

  println(instruction)

选择2:

 var Str = instruction + string2;

 println(Str)

参考这个

Answer 4

在某处添加此扩展程序:

extension String {
    mutating func addString(str: String) {
        self = self + str
    }
}

然后你可以这样称呼它:

var str1 = "hi"
var str2 = " my name is"
str1.addString(str2)
println(str1) //hi my name is

很多像这样的Swift扩展都在我的repo中,请查看它们:https://github.com/goktugyil/EZSwiftExtensions

Answer 5

您可以简单地追加字符串:

var worldArg = "world is good"

worldArg += " to live";