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This page contains review questions and answers for the page titled "Json0215: Encoding JSON Strings" in the book titled "The json-simple Java Library".

Revised: Sat Jun 04 12:48:39 CDT 2016

This page is included in the following Books:

Table of Contents

Preface

This is a page from the book titled The json-simple Java Library . The book explains how to use the json-simple Java library to generate, transform, and query JSON text. This page provides review questionsand answers for the page titled Json0215: Encoding JSON Strings . Once you study that page, you should be able to answer the review questions in this page.

The questions and the answers in this page are connected by hyperlinks to make it easy for you to navigate from the question to the answer and back again.

The figures and listings (if any) are grouped together. It is recommend that when a question or an answer refers to a figure or a listing, that you open it in a new window tomake it easy to view it while reading the question or the answer.

Questions

Question 1 .

True or False? Once you have an object of the class named JSONObject , you can call any of the methods defined in the HashMap class on that object.

Go to answer 1

Question 2

True or False? The code shown in Listing 1 produced the screen output shown in Figure 1 .

Go to answer 2

Question 3

True or False? The code shown in Listing 3 produced the screen output shown in Figure 3 .

Go to answer 3

Figure index

Listing index

What is the meaning of the following two images?

These images were inserted here simply to insert some space between the questions and the answers to keep them from being visible on the screen at thesame time.

Spacer image of a rabbit and a penguin.

This image was also inserted for the purpose of inserting space between the questions and the answers.

Spacer image of a penguin and some houses.

Answers

Answer 3

True. The code in Listing 3 uses the get method inherited from the HashMap class to get and display the values associated with the keys "name", "age", and "student".

Go back to Question 3

Answer 2

False. The code in Listing 1 produced the output with the compiler error message shown in Figure 2 . The output shown in in Figure 1 was produced by the code shown in Listing 2 . Note the call to the toJSONString method of the JSONObject class to extract the information from the JSONObject object and encode it into a JSON string.

Go back to Question 2

Answer 1

True. The class named JSONObject extends the standard Java class named HashMap . Therefore, the JSONObject class inherits all of the methods defined in the HashMap class.

Go back to Question 1

Figures

This section contains Figures that may be referred to by one or more questions or answers.

Figure 1

{"student":true,"name":"Joe","age":21}

Figure 2

Code01.java:20: error: no suitable method found for get(no arguments) String jsonString = jsonObject.get();

Figure 3

Joe 21true

Listings

This section contains Listings that may be referred to by one or more questions or answers.

Listing 1

import org.json.simple.JSONObject; class Code01 {public static void main(String[] args){JSONObject jsonObject= new JSONObject(); jsonObject.put("name","Joe");jsonObject.put("age",21); jsonObject.put("student",true);String jsonString = jsonObject.get(); System.out.println(jsonString);}//end main }//end class Code01

Listing 2

import org.json.simple.JSONObject; class Code02 {public static void main(String[] args){JSONObject jsonObject= new JSONObject(); jsonObject.put("name","Joe");jsonObject.put("age",21); jsonObject.put("student",true);String jsonString = jsonObject.toJSONString(); System.out.println(jsonString);}//end main }//end class Code02

Listing 3

import org.json.simple.JSONObject; class Code03 {public static void main(String[] args){JSONObject jsonObject= new JSONObject(); jsonObject.put("name","Joe");jsonObject.put("age",21); jsonObject.put("student",true);System.out.println(jsonObject.get("name")); System.out.println(jsonObject.get("age"));System.out.println(jsonObject.get("student")); }//end main}//end class Code03

Miscellaneous

This section contains a variety of miscellaneous information.

Housekeeping material
  • Module name: Json0215R: Review
  • File: Json0215R.htm
  • Published: 06/04/16
Disclaimers:

Financial : Although the Connexions site makes it possible for you to download aPDF file for this module at no charge, and also makes it possible for you to purchase a pre-printed version of the PDF file, youshould be aware that some of the HTML elements in this module may not translate well into PDF.

I also want you to know that, I receive no financial compensation from the Connexions website even if you purchase the PDF version ofthe module.

In the past, unknown individuals have copied my modules fromcnx.org, converted them to Kindle books, and placed them for sale on Amazon.com showing me as the author. I neither receive compensationfor those sales nor do I know who does receive compensation. If you purchase such a book, please be aware that it is a copy of a modulethat is freely available on cnx.org and that it was made and published without my prior knowledge.

Affiliation : I am a professor of Computer Information Technology at Austin Community College in Austin, TX.

-end-

Questions & Answers

find the 15th term of the geometric sequince whose first is 18 and last term of 387
Jerwin Reply
I know this work
salma
The given of f(x=x-2. then what is the value of this f(3) 5f(x+1)
virgelyn Reply
hmm well what is the answer
Abhi
how do they get the third part x = (32)5/4
kinnecy Reply
can someone help me with some logarithmic and exponential equations.
Jeffrey Reply
sure. what is your question?
ninjadapaul
20/(×-6^2)
Salomon
okay, so you have 6 raised to the power of 2. what is that part of your answer
ninjadapaul
I don't understand what the A with approx sign and the boxed x mean
ninjadapaul
it think it's written 20/(X-6)^2 so it's 20 divided by X-6 squared
Salomon
I'm not sure why it wrote it the other way
Salomon
I got X =-6
Salomon
ok. so take the square root of both sides, now you have plus or minus the square root of 20= x-6
ninjadapaul
oops. ignore that.
ninjadapaul
so you not have an equal sign anywhere in the original equation?
ninjadapaul
hmm
Abhi
is it a question of log
Abhi
🤔.
Abhi
I rally confuse this number And equations too I need exactly help
salma
But this is not salma it's Faiza live in lousvile Ky I garbage this so I am going collage with JCTC that the of the collage thank you my friends
salma
Commplementary angles
Idrissa Reply
hello
Sherica
im all ears I need to learn
Sherica
right! what he said ⤴⤴⤴
Tamia
hii
Uday
hi
salma
what is a good calculator for all algebra; would a Casio fx 260 work with all algebra equations? please name the cheapest, thanks.
Kevin Reply
a perfect square v²+2v+_
Dearan Reply
kkk nice
Abdirahman Reply
algebra 2 Inequalities:If equation 2 = 0 it is an open set?
Kim Reply
or infinite solutions?
Kim
The answer is neither. The function, 2 = 0 cannot exist. Hence, the function is undefined.
Al
y=10×
Embra Reply
if |A| not equal to 0 and order of A is n prove that adj (adj A = |A|
Nancy Reply
rolling four fair dice and getting an even number an all four dice
ramon Reply
Kristine 2*2*2=8
Bridget Reply
Differences Between Laspeyres and Paasche Indices
Emedobi Reply
No. 7x -4y is simplified from 4x + (3y + 3x) -7y
Mary Reply
how do you translate this in Algebraic Expressions
linda Reply
Need to simplify the expresin. 3/7 (x+y)-1/7 (x-1)=
Crystal Reply
. After 3 months on a diet, Lisa had lost 12% of her original weight. She lost 21 pounds. What was Lisa's original weight?
Chris Reply
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Source:  OpenStax, Object-oriented programming (oop) with java. OpenStax CNX. Jun 29, 2016 Download for free at https://legacy.cnx.org/content/col11441/1.201
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