Reputation: 10563

Convert NSNumber to int in Objective-C

I use [NSNumber numberWithInt:42] or @(42) to convert an int to NSNumber before adding it to an NSDictionary:

int intValue = 42;
NSNumber *numberValue = [NSNumber numberWithInt:intValue];
NSDictionary *dict = @{ @"integer" : numberValue };

When I retrieve the value from the NSDictionary, how can I transform it from NSNumber back to int?

NSNumber *number = dict[@"integer"];
int *intNumber = // ...?

It throws an exception saying casting is required when I do it this way:

int number = (int)dict[@"integer"];

Upvotes: 132

Answers (5)

Reputation: 782

A less verbose approach:

int number = [dict[@"integer"] intValue];

Upvotes: 1

Reputation: 817208

Have a look at the documentation. Use the intValue method:

NSNumber *number = [dict objectForKey:@"integer"];
int intValue = [number intValue];

Upvotes: 207

Reputation: 6177

A tested one-liner:

int number = ((NSNumber*)[dict objectForKey:@"integer"]).intValue;

Upvotes: 0

Reputation: 9364

You should stick to the NSInteger data types when possible. So you'd create the number like that:

NSInteger myValue = 1;
NSNumber *number = [NSNumber numberWithInteger: myValue];

Decoding works with the integerValue method then:

NSInteger value = [number integerValue];

Upvotes: 62

Reputation: 5676

Use the NSNumber method intValue

Upvotes: 3