How do I convert an NSString value to NSData?

Do:

NSData *data = [yourString dataUsingEncoding:NSUTF8StringEncoding];

then feel free to proceed with `NSJSONSerialization:JSONObjectWithData`.

---

###Correction to the answer regarding the NULL terminator

Following the comments, official documentation, and [verifications](

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), this answer was updated regarding the removal of an alleged NULL terminator:

1. As documented by [dataUsingEncoding:](

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):
>###Return Value
The result of invoking `dataUsingEncoding:allowLossyConversion:` with NO as the second argument

2. As documented by [getCString:maxLength:encoding:](

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) and [cStringUsingEncoding:](

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):
>note that the data returned by `dataUsingEncoding:allowLossyConversion:` is not a strict C-string since it **does not have a NULL terminator**

**Objective-C:**

NSString to NSData:

NSString* str= @"string";
NSData* data=[str dataUsingEncoding:NSUTF8StringEncoding];

NSData to NSString:

NSString* newStr = [[NSString alloc] initWithData:theData encoding:NSUTF8StringEncoding];


**Swift:**

String to Data:

var testString = "string"
var somedata = testString.data(using: String.Encoding.utf8)

Data to String:

var backToString = String(data: somedata!, encoding: String.Encoding.utf8) as String!

Update Swift 5.x

let str = "teststring"
let data = str.data(using: .utf8)

In Swift there is an API which returns a **non-optional**

let str = "teststring"
let data = Data(str.utf8)

<b>Swift:</b>

Swift 5.x

```
let myStringToConvert = "My String to Convert in Data"
let myData = myStringToConvert.data(using: .utf8)
```


String to Data:

```
var myStringToConvert = "My String to Convert in Data"
var myData = myStringToConvert.data(using: String.Encoding.utf8)
```

Data to String:

```
var backToMyString = String(data: myData!, encoding: String.Encoding.utf8) as String!
```

<b>OBJECTIVE C:</b>

NSString to NSData :

```
NSString* myStringToConvert= @"My String to Convert in Data";
NSData* myData=[str dataUsingEncoding:NSUTF8StringEncoding allowLossyConversion:NO];
```

NSData to NSString :

```
NSString* backToMyString = [[NSString alloc] initWithData: myData encoding:NSUTF8StringEncoding];
```