Objective-C

JSON: Nested Array

See more JSON Examples

Here we have a JSON object that contains nested arrays. This example demonstrates how to access the contents of the nested arrays.

{
 "numbers" : [ 
    ["even", 2, 4, 6, 8], 
    ["prime", 2, 3, 5, 7, 11, 13] 
  ] }

Objective-C

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

BOOL success = NO;

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

// This is the above JSON with whitespace chars removed (SPACE, TAB, CR, and LF chars).
// The presence of whitespace chars for pretty-printing makes no difference to the Load
// method. 
NSString *jsonStr = @"{ \"numbers\" : [ [\"even\", 2, 4, 6, 8], [\"prime\", 2, 3, 5, 7, 11, 13] ] }";

success = [json Load: jsonStr];
if (success != YES) {
    NSLog(@"%@",json.LastErrorText);
    return;
}

// Get the value of the "numbers" object, which is an array that contains JSON arrays.
CkoJsonArray *outerArray = [json ArrayOf: @"numbers"];
if (json.LastMethodSuccess == NO) {
    NSLog(@"%@",@"numbers array not found.");
    return;
}

int numArrays = [outerArray.Size intValue];
int i;

for (i = 0; i <= numArrays - 1; i++) {

    CkoJsonArray *innerArray = [outerArray ArrayAt: [NSNumber numberWithInt: i]];

    // The first item in the innerArray is a string
    NSLog(@"%@%@",[innerArray StringAt: [NSNumber numberWithInt: 0]],@":");

    int numInnerItems = [innerArray.Size intValue];
    int j;
    for (j = 1; j <= numInnerItems - 1; j++) {

        NSLog(@"%@%d",@"  ",[[innerArray IntAt: [NSNumber numberWithInt: j]] intValue]);

    }

}