Computer Programming CS 102 Midterms Reviewer

Vocabulary flashcards covering core concepts from Computer Programming CS 102 midterms reviewer, including programming basics, algorithms, C language components, streams, formatted I/O, and file processing.

Computer Programming

Writing instructions and giving them to the computer to complete a task (i.e. software).

Operating System

Manages computer hardware and software resources.

Compilers and Interpreters

Translate high-level code into machine language.

Applications

Executes a specific user-driven task.

Embedded Systems

Controls the physical hardware of a dedicated device.

Compiler

Translates the whole program once before executing.

Interpreter

Translates and executes the program one line at a time.

Source Code

Human-understandable program.

Object Code

Machine-understandable program.

Problem-Solving Phase

The initial phase of programming consisting of Defining Problem (determine program function and requirements) and Designing Program (make an algorithm).

Implementation Phase

The phase of programming consisting of Coding (express algorithm into programming language, translate source code into object code) and Testing and Debugging (find out if output is correct, search for bugs/errors).

High-Level Language

Uses English-like words, mathematical symbols, and familiar syntax.

Low-Level Language

Interacts directly with the CPU, registers, and memory addresses.

Algorithm

A sequence of instructions describing how to do a task.

Values and Variables

Values may be any quantities, measurements, or data. Variables contain values.

Instructions (Algorithm)

Action that is simple (primitives); manipulates/controls the variable or value.

Sequence

A series of instructions.

Procedure

Sequence, function, sub-routine, or module. Braces are used to mark its beginning and end. Procedure call invokes it, and procedures can have parameters.

Selection

Instruction that decides which sequence is executed based on a true/false condition.

Repetition

Repeats an instruction while or until a true or false condition occurs; also called iterations or loops.

Documentation (Algorithm)

Describes what the algorithm does.

Nested Selection

Inner condition is only checked if the outer condition is true. Used when the 2nd condition depends on whether the statement is true.

Cascaded Selection

Program checks conditions from top to bottom until it finds a true condition. Used when $2$ or more conditions cannot all be true.

Pretest vs Posttest Loops

Pretest checks condition first before running (may run $0$ times). Posttest runs once, then checks condition.

Structured English

Expressing your algorithm in plain English through a numbered sequence.

Pseudocode

Describing the steps in your algorithm by incorporating logical symbols and operators.

Flowchart

Pictorial representation of algorithms.

Six Basic Computer Operations

1. Receive inputs; 2. Output information; 3. Perform arithmetic operations; 4. Assign value; 5. Compare information; 6. Repeat actions.

Algorithm vs Program

Algorithm is for talking to humans (plain language, pseudocode, or flowcharts). Program is for talking to computers ("Formal Expression" of an algorithm).

Linker

Assembles all functions into a final executable program.

Basic Structure of a C Program

Consists of library inclusion #include <stdio.h>, main function declaration int main(), braces enclosing instructions, and return 0;.

Modulo Operator

Denoted by \%; calculates the remainder of division.

Integer Division Rule

If you divide $2$ integers, the program will not round.

Comments in C

Syntax: /*Comment*/. Comments do not nest.

ASCII Values Range

Range from $0$ to $127$. Capital letters: A($65$) to Z($90$). Small letters: a($97$) to z($122$).

Identifiers

Names of variables. Qualities: Any letter, number, or _; cannot start with a digit; not a keyword; case-sensitive.

Boolean Values in C

Either true ($1$ or any non-zero integer) or false ($0$).

Operator Precedence

Order: Brackets > Arithmetic > ! > < > <= >= > == > != > && > || > =.

Stream

Sequence of characters that acts as a channel between your program and I/O devices (e.g. keyboard, monitor), organized into lines that end with \n.

Standard Streams

stdin: Standard input (e.g. keyboard); stdout: Standard output (e.g. monitor); stderr: Standard error (e.g. monitor).

scanf()

Reads data from stdin. Syntax: scanf("[conversion specifiers]", &[variable type]);. Don't use & when reading strings.

printf()

Writes data from stdout. Syntax: printf("[literals and conversion specifiers]", variable). Don't use & in variable types.

Conversion Specifiers

%d and %i (Integers), %f (Float), %e (Float in exponential form), %c (Character), %s (String), %x (Hexadecimals), %o (Octals), %% (Prints literal %).

Text file vs Binary File

Text file (.txt): Stores data as ASCII characters, ends lines with \n. Binary File (.bin): Stores data in raw binary format ($0$s and $1$s), created and read through C programs.

Steps for File Processing

1. Open file stream using fopen(); 2. Read/write data using standard file stream functions; 3. Close the file stream using fclose().

fopen()

Opens a file stream. Syntax: FILE *fptr = fopen ("filename", "mode");. Text Modes: r/rt (read), w/wt (write), a/at (append). Binary Modes: rb (read), wb (write), ab (append).

fclose()

Closes a file stream. Syntax: fclose (fptr);. Releases the file pointer and saves changes.

fprintf()

Functions like printf(), but takes the file pointer as its first argument to write formatted output to a file stream.

fscanf()

Functions like scanf(), but reads input from a file pointer instead of standard console input.