Android™

Get the Index of a JSON Member

See more JSON Examples

This example demonstrates how to get the index of a given member by name.

{
  "name": "donut",
  "image":
    {
    "fname": "donut.jpg",
    "w": 200,
    "h": 200
    },
  "thumbnail":
    {
    "fname": "donutThumb.jpg",
    "w": 32,
    "h": 32
    }
}

Android™

// Important: Don't forget to include the call to System.loadLibrary
// as shown at the bottom of this code sample.
package com.test;

import android.app.Activity;
import com.chilkatsoft.*;

import android.widget.TextView;
import android.os.Bundle;

public class SimpleActivity extends Activity {

  private static final String TAG = "Chilkat";

  // Called when the activity is first created.
  @Override
  public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    boolean success = false;

    CkJsonObject json = new CkJsonObject();

    // 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. 
    String jsonStr = "{\"name\": \"donut\",\"image\":{\"fname\": \"donut.jpg\",\"w\": 200,\"h\": 200},\"thumbnail\":{\"fname\": \"donutThumb.jpg\",\"w\": 32,\"h\": 32}}";

    success = json.Load(jsonStr);
    if (success == false) {
        Log.i(TAG, json.lastErrorText());
        return;
        }

    // The top-level JSON object has three members: name, image, and thumbnail.
    int nameIndex = json.IndexOf("name");
    // The index of the "name" member is 0.
    Log.i(TAG, "nameIndex = " + String.valueOf(nameIndex));

    int thumbIndex = json.IndexOf("thumbnail");
    // The index of the "thumbnail" member is 2.
    Log.i(TAG, "thumbIndex = " + String.valueOf(thumbIndex));

    // The "fname" member is NOT a direct member of the top-level JSON object.
    // It is a member of a nested object.  If we try to get the index of this
    // member using the top-level JSON object, it is not found (and returns -1).
    int fnameIndex = json.IndexOf("fname");
    // The fnameIndex is -1 (not found).  This is correct.
    Log.i(TAG, "fnameIndex = " + String.valueOf(fnameIndex));

    // Get the "image" object.
    CkJsonObject imageObj = new CkJsonObject();
    json.ObjectOf2("image",imageObj);

    // Now we can get the index of the "fname" object, because it is a direct
    // member of the "image" object:
    fnameIndex = imageObj.IndexOf("fname");
    Log.i(TAG, "fnameIndex = " + String.valueOf(fnameIndex));

  }

  static {
      System.loadLibrary("chilkat");

      // Note: If the incorrect library name is passed to System.loadLibrary,
      // then you will see the following error message at application startup:
      //"The application <your-application-name> has stopped unexpectedly. Please try again."
  }
}