CS Chapter 1

Question 1

What is computational thinking?

Answer 1

the thought process needed to build correct, precise, logical programs

Question 2

When was Java first publicly released? Who was the main developer?

Answer 2

1995; James Gosling

Question 3

What is a computer program?

Answer 3

specific set of ordered operations for a computer to perform

Question 4

What is input?

Answer 4

a program gets data from the user (through keyboard, touchscreen, etc.)

Question 5

What is process in terms of input and output?

Answer 5

A program performs computations on the user input data, such as adding two values like x + y

Question 6

What is output?

Answer 6

A program puts that data somewhere, such as to a file, screen, network, etc.

Question 7

Variable

Answer 7

used to store information to be referenced and manipulated in a computer program

Question 8

Algorithm

Answer 8

a sequence of instructions that solves a problem

Question 9

Problem solving

Answer 9

creating a methodical solution to a given task

Question 10

main()

Answer 10

entry point to start the execution of a program; executes program within its curly braces

Question 11

semicolon

Answer 11

placed at the end of every statement, as English sentences end with a period

Question 12

What code enables a program to get input?

Answer 12

import java.util.Scanner;

Question 13

Scanner

Answer 13

Java class used to obtain input from the user in the form of words, number, and phrases

Question 14

How to use Scanner

Answer 14

Scanner scnr (or any name) = new Scanner(System.in);

x = scnr.nextInt();

Question 15

string literal

Answer 15

text in “double quotes”

Question 16

System.out.print(“”) vs System.out.println(“”)

Answer 16

System.out.println() starts a new line after the desired text

Question 17

newline character

Answer 17

\n; written within string literals to being new lines. Ex. 1\n2\n3\n

Question 18

Comment

Answer 18

Text a programmer adds to code, to be read by humans to better understand the code but ignored by the compiler

Question 19

single-line comment

Answer 19

starts with // and includes all the following text on that line; commonly appear after a statement on the same line

Question 20

multi-line comment

Answer 20

starts with /* and ends with */, where all the text in between is part of the comment; also known as a block comment

Question 21

Whitespace

Answer 21

refers to blank spaces between items within a statement and blank lines between statements; mostly ignored by compiler

Question 22

Whitespace Guidelines

Answer 22

1. Use blank lines to separate conceptually distinct statements
2. Indent lines the same amount
3. Align items to reduce visual clutter
4. Use a single space before and after any operators to make statements more readable

Question 23

Compiler

Answer 23

converts high level program into executable program using Java bytecode; scans code line-by-line; recognizes end of statement by semicolon; ignores comments and most whitespace

Question 24

Syntax error

Answer 24

violate programming rules on how symbols can be combined to create a program; ex. forgetting to use semicolon, uninitialized and undefined variable

Question 25

Good Practice for fixing errors reported by the compiler

Answer 25

1. Focus on FIRST error message, ignoring the rest. 2. Look at reported line of first error message. If error found, fix. Else, look at previous few lines. 3. Compile, repeat.

Question 26

Logic errors

Answer 26

error (bug) that occurs while a program is running; program doesn't run as intended; sometimes indicated by compiler warning

Question 27

What practice, involving compiling is good for beginners?

Answer 27

compiling frequently after writing a few lines of code will prevent too many errors from occurring

Question 28

javac -Xlint yourfile.java

Answer 28

enables all recommended warnings