Objective-C

Check if Integer Exists at JSON Path

Demonstrates how to get an integer value at a JSON path, and how to check to see if it exists. Objective-C

#import <CkoJsonObject.h>
#import <NSString.h>

BOOL success = NO;

CkoJsonObject *json = [[CkoJsonObject alloc] init];

//  First build simple JSON..
[json UpdateInt: @"test.abc" value: [NSNumber numberWithInt: 100]];

json.EmitCompact = NO;
NSLog(@"%@",[json Emit]);

//  This is our JSON:
//  {
//    "test": {
//      "abc": 100,
//    }
//  }

NSString *path = @"test.notHere";

//  The call to IntOf will return 0, because it's not present.
//  But how do we know if it really was present, and the value was truly 0?
int val = [[json IntOf: path] intValue];
NSLog(@"%@%d",@"val = ",val);

//  We cannot use LastMethodSuccess because LastMethodSuccess only applies
//  to methods that:
//  - return a string
//  - return a new Chilkat object, binary bytes, or a date/time.
//  - returns a boolean status where true = success and false = failed.
//  - returns an integer where failure is defined by a return value less than zero.
//  The IntOf method fits none of these requirements, and therefore the LastMethodSuccess 
//  is not a valid indicator..
BOOL wasFound = json.LastMethodSuccess;
NSLog(@"%@%d%@",@"wasFound = ",wasFound,@" (not a valid indicator)");

//  Instead, if the returned value is 0, we can double-check to see if the member was truly there..
if (val == 0) {
    wasFound = [json HasMember: path];
    NSLog(@"%@%d",@"wasFound = ",wasFound);
    if (wasFound == YES) {
        NSLog(@"%@",@"The value was present and is 0.");
    }
    else {
        NSLog(@"%@",@"no member is present at test.notHere");
    }

}
else {
    NSLog(@"%@%d",@"val = ",val);
}

//  Alternatively, you could check to see if the member exists beforehand..
if ([json HasMember: path] == YES) {
    NSLog(@"%@%d",@"val = ",[[json IntOf: path] intValue]);
}
else {
    NSLog(@"%@%@",@"no member at ",path);
}