blocks|key|104216|text|在Swift中，附加字符串非常简单：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|104217|let+stringA+=+"this+is+a+string"
let+stringB+=+"this+is+also+a+string"
let+stringC+=+stringA+%2B+stringB|code-block|syntax|javascript|104218|或者，您可以使用字符串插值。|104219|let+stringC+=+"\(stringA)+\(stringB)"|104220|请注意，它们之间现在将有空格。|104221|注意:我发现其他答案都在大量使用var。字符串没有改变，因此应该使用let声明。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的一大特点。|offset|length|style|CODE|104222|entityMap^0|0|0|0|0|0|G|3|Y|3|0^^$0|@$1|2|3|4|5|6|7|U|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|V|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|W|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|X|8|@]|9|@]|A|$E|F]]|$1|K|3|L|5|6|7|Y|8|@]|9|@]|A|$]]|$1|M|3|N|5|6|7|Z|8|@$O|10|P|11|Q|R]|$O|12|P|13|Q|R]]|9|@]|A|$]]|$1|S|3|-4|5|6|7|14|8|@]|9|@]|A|$]]]|T|$]]

In Swift, appending strings is as easy as:

<pre><code>let stringA = "this is a string"
let stringB = "this is also a string"
let stringC = stringA + stringB
</code></pre>

Or you can use string interpolation.

<pre><code>let stringC = "\(stringA) \(stringB)"
</code></pre>

Notice there will now be whitespace between them.

Note: I see the other answers are using <code>var</code> a lot. The strings aren't changing and therefore should be declared using <code>let</code>. I know this is a small exercise, but it's good to get into the habit of best practices. Especially because that's a big feature of Swift.

blocks|key|104239|text|let+string2+=+"+there"
var+instruction+=+"look+over"|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|104240|选项1：|unstyled|104241|+instruction+%2B=+string2;

++println(instruction)|104242|选项2：|104243|+var+Str+=+instruction+%2B+string2;

+println(Str)|104244|参考this|offset|length|104245|entityMap|0|LINK|mutability|MUTABLE|url|https://developer.apple.com/library/prerelease/ios/documentation/swift/conceptual/swift_programming_language/StringsAndCharacters.html^0|0|0|0|0|0|2|4|0|0^^$0|@$1|2|3|4|5|6|7|Y|8|@]|9|@]|A|$B|C]]|$1|D|3|E|5|F|7|Z|8|@]|9|@]|A|$]]|$1|G|3|H|5|6|7|10|8|@]|9|@]|A|$B|C]]|$1|I|3|J|5|F|7|11|8|@]|9|@]|A|$]]|$1|K|3|L|5|6|7|12|8|@]|9|@]|A|$B|C]]|$1|M|3|N|5|F|7|13|8|@]|9|@$O|14|P|15|1|16]]|A|$]]|$1|Q|3|-4|5|F|7|17|8|@]|9|@]|A|$]]]|R|$S|$5|T|U|V|A|$W|X]]]]

<pre><code>let string2 = " there"
var instruction = "look over"
</code></pre>

choice 1 :

<pre><code> instruction += string2;

 println(instruction)
</code></pre>

choice 2:

<pre><code> var Str = instruction + string2;

 println(Str)
</code></pre>

ref <a href="https://developer.apple.com/library/prerelease/ios/documentation/swift/conceptual/swift_programming_language/StringsAndCharacters.html" rel="noreferrer">this</a>

blocks|key|104309|text|在某个地方添加此扩展：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|104310|extension+String+{
++++mutating+func+addString(str:+String)+{
++++++++self+=+self+%2B+str
++++}
}|code-block|syntax|javascript|104311|然后你可以这样叫它：|104312|var+str1+=+"hi"
var+str2+=+"+my+name+is"
str1.addString(str2)
println(str1)+//hi+my+name+is|104313|在我的资源库中有很多像这样的Swift扩展，请查看它们：https://github.com/goktugyil/EZSwiftExtensions|offset|length|104314|entityMap|0|LINK|mutability|MUTABLE|url|https://github.com/goktugyil/EZSwiftExtensions^0|0|0|0|0|S|1A|0|0^^$0|@$1|2|3|4|5|6|7|W|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|X|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|Y|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|Z|8|@]|9|@]|A|$E|F]]|$1|K|3|L|5|6|7|10|8|@]|9|@$M|11|N|12|1|13]]|A|$]]|$1|O|3|-4|5|6|7|14|8|@]|9|@]|A|$]]]|P|$Q|$5|R|S|T|A|$U|V]]]]

Add this extension somewhere:

<pre><code>extension String {
 mutating func addString(str: String) {
 self = self + str
 }
}
</code></pre>

Then you can call it like:

<pre><code>var str1 = "hi"
var str2 = " my name is"
str1.addString(str2)
println(str1) //hi my name is
</code></pre>

A lot of good Swift extensions like this are in my repo here, check them out: <a href="https://github.com/goktugyil/EZSwiftExtensions" rel="nofollow">https://github.com/goktugyil/EZSwiftExtensions</a>

blocks|key|4610883|text|您可以简单地附加字符串，如下所示：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|4610884|var+worldArg+=+"world+is+good"

worldArg+%2B=+"+to+live";|code-block|syntax|javascript|4610885|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

You can simply append string
like:

<pre><code>var worldArg = "world is good"

worldArg += " to live";
</code></pre>

blocks|key|104183|text|var+string1+=+"This+is+";
var+string2+=+"Swift+Language";
var+appendString+=+string1+%2B+string2;
println("APPEND+STRING:+\(appendString)");|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|104184|unstyled|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|G|8|@]|9|@]|A|$B|C]]|$1|D|3|-4|5|E|7|H|8|@]|9|@]|A|$]]]|F|$]]

<pre><code>var string1 = "This is ";
var string2 = "Swift Language";
var appendString = string1 + string2;
println("APPEND STRING: \(appendString)");
</code></pre>

blocks|key|104411|text|根据Swift+4+Documentation，字符串值可以与加法运算符(%2B)相加(或连接)以创建新的字符串值：|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|104412|let+string1+=+"hello"
let+string2+=+"+there"
var+welcome+=+string1+%2B+string2
//+welcome+now+equals+"hello+there"|code-block|syntax|javascript|104413|还可以使用加法赋值运算符(%2B=)将字符串值附加到现有字符串变量：|104414|var+instruction+=+"look+over"
instruction+%2B=+string2
//+instruction+now+equals+"look+over+there"|104415|可以使用字符串类型的append()方法将字符值附加到字符串变量：|104416|let+exclamationMark:+Character+=+"!"
welcome.append(exclamationMark)
//+welcome+now+equals+"hello+there!"|104417|entityMap|0|LINK|mutability|MUTABLE|url|https://developer.apple.com/library/content/documentation/Swift/Conceptual/Swift_Programming_Language/StringsAndCharacters.html^0|2|L|0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|Y|8|@]|9|@$A|Z|B|10|1|11]]|C|$]]|$1|D|3|E|5|F|7|12|8|@]|9|@]|C|$G|H]]|$1|I|3|J|5|6|7|13|8|@]|9|@]|C|$]]|$1|K|3|L|5|F|7|14|8|@]|9|@]|C|$G|H]]|$1|M|3|N|5|6|7|15|8|@]|9|@]|C|$]]|$1|O|3|P|5|F|7|16|8|@]|9|@]|C|$G|H]]|$1|Q|3|-4|5|6|7|17|8|@]|9|@]|C|$]]]|R|$S|$5|T|U|V|C|$W|X]]]]

According to <a href="https://developer.apple.com/library/content/documentation/Swift/Conceptual/Swift_Programming_Language/StringsAndCharacters.html" rel="nofollow noreferrer">Swift 4 Documentation</a>,
String values can be added together (or concatenated) with the addition operator (+) to create a new String value:

<pre><code>let string1 = "hello"
let string2 = " there"
var welcome = string1 + string2
// welcome now equals "hello there"
</code></pre>

You can also append a String value to an existing String variable with the addition assignment operator (+=):

<pre><code>var instruction = "look over"
instruction += string2
// instruction now equals "look over there"
</code></pre>

You can append a Character value to a String variable with the String type’s append() method:

<pre><code>let exclamationMark: Character = "!"
welcome.append(exclamationMark)
// welcome now equals "hello there!"
</code></pre>

blocks|key|4610968|text|在被接受的答案中，PREMKUMAR在Swift+answer中的完整代码中有几个错误。第一次打印应为(appendString)，第二次打印应为(appendString1)。此外，更新后的println在Swift+2.0中已弃用|type|unstyled|depth|inlineStyleRanges|entityRanges|data|4610969|他的|4610970|let+string1+=+"This+is"
let+string2+=+"Swift+Language"
var+appendString+=+"\(string1)+\(string2)"
var+appendString1+=+string1%2Bstring2
println("APPEND+STRING1:\(appendString1)")
println("APPEND+STRING2:\(appendString2)")|code-block|syntax|javascript|4610971|已更正|4610972|let+string1+=+"This+is"
let+string2+=+"Swift+Language"
var+appendString+=+"\(string1)+\(string2)"
var+appendString1+=+string1%2Bstring2
print("APPEND+STRING:\(appendString)")
print("APPEND+STRING1:\(appendString1)")|4610973|entityMap^0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|O|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|P|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|Q|8|@]|9|@]|A|$G|H]]|$1|I|3|J|5|6|7|R|8|@]|9|@]|A|$]]|$1|K|3|L|5|F|7|S|8|@]|9|@]|A|$G|H]]|$1|M|3|-4|5|6|7|T|8|@]|9|@]|A|$]]]|N|$]]

In the accepted answer PREMKUMAR there are a couple of errors in his Complete code in Swift answer. First print should read (appendString) and Second print should read (appendString1). Also, updated println deprecated in Swift 2.0

His

<pre><code>let string1 = "This is"
let string2 = "Swift Language"
var appendString = "\(string1) \(string2)"
var appendString1 = string1+string2
println("APPEND STRING1:\(appendString1)")
println("APPEND STRING2:\(appendString2)")
</code></pre>

Corrected

<pre><code>let string1 = "This is"
let string2 = "Swift Language"
var appendString = "\(string1) \(string2)"
var appendString1 = string1+string2
print("APPEND STRING:\(appendString)")
print("APPEND STRING1:\(appendString1)")
</code></pre>

blocks|key|4610977|text|let+firstname+=+"paresh"
let+lastname+=+"hirpara"
let+itsme+=+"\(firstname)+\(lastname)"|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|4610978|unstyled|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|G|8|@]|9|@]|A|$B|C]]|$1|D|3|-4|5|E|7|H|8|@]|9|@]|A|$]]]|F|$]]

<pre><code>let firstname = "paresh"
let lastname = "hirpara"
let itsme = "\(firstname) \(lastname)"
</code></pre>

I am new to iOS. I am currently studying iOS using Objective-C and Swift.

To append a string in Objective-C I am using following code:

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

Anyone please guide me.

Append String in Swift

Objective-C

Swift

我是iOS的新手。我目前正在使用Objective-C和Swift学习iOS。为了在Objective-C中追加一个字符串，我使用了以下代码： NSString *string1 = @"This is"; NSString *string2 = @"Swift Language"; NSString *appendString=[NSString stringWithFormat:@"%@ %@

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