blocks|key|4618176|text|您可以像这样从String桥接到NSString，并将其从CInt转换为Int：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|4618177|var+myint:+Int+=+Int(stringNumb.bridgeToObjectiveC().intValue)|code-block|syntax|javascript|4618178|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 bridge from String to NSString and convert from CInt to Int like this:

<pre><code>var myint: Int = Int(stringNumb.bridgeToObjectiveC().intValue)
</code></pre>

blocks|key|112106|text|如果您只能使用NSString。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|112107|它非常类似于objective-c。所有数据类型都已存在，但需要添加as+NSString|112108|++++var+x+=+"400.0"+as+NSString+

++++x.floatValue+//string+to+float
++++x.doubleValue+//+to+double
++++x.boolValue+//+to+bool
++++x.integerValue+//+to+integer
++++x.intValue+//+to+int|code-block|syntax|javascript|112109|此外，我们还添加了一个toInt()功能，请参阅苹果公司。“Swift编程语言。”iBooks。https://itun.es/us/jEUH0.l第49页|112110|x.toInt()|112111|entityMap|0|LINK|mutability|MUTABLE|url|https://itun.es/us/jEUH0.l^0|7|8|0|Y|B|0|0|B|7|1C|Q|0|0|0^^$0|@$1|2|3|4|5|6|7|Y|8|@$9|Z|A|10|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|11|8|@$9|12|A|13|B|C]]|D|@]|E|$]]|$1|H|3|I|5|J|7|14|8|@]|D|@]|E|$K|L]]|$1|M|3|N|5|6|7|15|8|@$9|16|A|17|B|C]]|D|@$9|18|A|19|1|1A]]|E|$]]|$1|O|3|P|5|J|7|1B|8|@]|D|@]|E|$K|L]]|$1|Q|3|-4|5|6|7|1C|8|@]|D|@]|E|$]]]|R|$S|$5|T|U|V|E|$W|X]]]]

If you are able to use a <code>NSString</code> only.

It's pretty similar to objective-c. All the data type are there but require the <code>as NSString</code> addition

<pre><code> var x = "400.0" as NSString 

 x.floatValue //string to float
 x.doubleValue // to double
 x.boolValue // to bool
 x.integerValue // to integer
 x.intValue // to int
</code></pre>

Also we have an <code>toInt()</code> function added See Apple Inc. “The Swift Programming Language.” iBooks. <a href="https://itun.es/us/jEUH0.l">https://itun.es/us/jEUH0.l</a> page 49

<pre><code>x.toInt()
</code></pre>

blocks|key|4618243|text|您想要的方法是toInt()+--您必须稍微小心一点，因为toInt()返回一个可选的Int。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|4618244|let+stringNumber+=+"1234"
let+numberFromString+=+stringNumber.toInt()
//+numberFromString+is+of+type+Int?+with+value+1234

let+notANumber+=+"Uh+oh"
let+wontBeANumber+=+notANumber.toInt()
//+wontBeANumber+is+of+type+Int?+with+value+nil|code-block|syntax|javascript|4618245|entityMap^0|7|7|T|7|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@$9|N|A|O|B|C]|$9|P|A|Q|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|R|8|@]|D|@]|E|$I|J]]|$1|K|3|-4|5|6|7|S|8|@]|D|@]|E|$]]]|L|$]]

The method you want is <code>toInt()</code> -- you have to be a little careful, since the <code>toInt()</code> returns an optional Int.

<pre><code>let stringNumber = "1234"
let numberFromString = stringNumber.toInt()
// numberFromString is of type Int? with value 1234

let notANumber = "Uh oh"
let wontBeANumber = notANumber.toInt()
// wontBeANumber is of type Int? with value nil
</code></pre>

blocks|key|112178|text|更通用的解决方案可以是扩展|type|unstyled|depth|inlineStyleRanges|entityRanges|data|112179|extension+String+{
++++var+toFloat:Float+{
++++++++return+Float(self.bridgeToObjectiveC().floatValue)
++++}
++++var+toDouble:Double+{
++++++++....
++++}
++++....
}|code-block|syntax|javascript|112180|例如，这通过toFloat扩展了swift原生字符串对象|112181|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|L|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|M|8|@]|9|@]|A|$]]|$1|I|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|J|$]]

A more general solution could be a extension

<pre><code>extension String {
 var toFloat:Float {
 return Float(self.bridgeToObjectiveC().floatValue)
 }
 var toDouble:Double {
 ....
 }
 ....
}
</code></pre>

this for example extends the swift native String object by toFloat

blocks|key|112186|text|为此，我编写了一个扩展。它总是返回一个Int。如果字符串不适合Int，则返回0。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|112187|extension+String+{
++++func+toTypeSafeInt()+->+Int+{
++++++++if+let+safeInt+=+self.toInt()+{
++++++++++++return+safeInt
++++++++}+else+{
++++++++++++return+0
++++++++}
++++}
}|code-block|syntax|javascript|112188|entityMap^0|J|3|V|3|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@$9|N|A|O|B|C]|$9|P|A|Q|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|R|8|@]|D|@]|E|$I|J]]|$1|K|3|-4|5|6|7|S|8|@]|D|@]|E|$]]]|L|$]]

I wrote an extension for that purpose. It always returns an <code>Int</code>. If the string does not fit into an <code>Int</code>, 0 is returned.

<pre><code>extension String {
 func toTypeSafeInt() -&gt; Int {
 if let safeInt = self.toInt() {
 return safeInt
 } else {
 return 0
 }
 }
}
</code></pre>

blocks|key|4618304|text|在Swift+2.0中将字符串转换为Int：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|4618305|var+str:NSString+=+Data+as!+NSString
var+cont:Int+=+str.integerValue|code-block|syntax|javascript|4618306|使用.intergerValue+or+intValue+for+Int32|offset|length|style|CODE|4618307|entityMap^0|0|0|2|10|0^^$0|@$1|2|3|4|5|6|7|O|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|Q|8|@$I|R|J|S|K|L]]|9|@]|A|$]]|$1|M|3|-4|5|6|7|T|8|@]|9|@]|A|$]]]|N|$]]

Convert String to Int in Swift 2.0:

<pre><code>var str:NSString = Data as! NSString
var cont:Int = str.integerValue
</code></pre>

use <code>.intergerValue or intValue for Int32</code>

So I can do this:

<pre><code>var stringNumb: NSString = "1357"

var someNumb: CInt = stringNumb.intValue
</code></pre>

But I can't find the way to do it w/ a <code>String</code>. I'd like to do something like:

<pre><code>var stringNumb: String = "1357"

var someNumb: Int = Int(stringNumb)
</code></pre>

This doesn't work either:

<pre><code>var someNumbAlt: Int = myString.integerValue
</code></pre>

Get integer value from string in swift

Swift

所以我可以这样做：var stringNumb: NSString = "1357"var someNumb: CInt = stringNumb.intValue但是我找不到用String做这件事的方法。我想做一些类似的事情：var stringNumb: String = "1357"var someNumb: I...

问在swift中从字符串中获取整数值
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