Exam 1 cs

Brain of computer. Uses instructions from memory. Speed measured in gigahertz

Stores data. 0s and 1s (on and off switches)

The minimum storage in a computer. Holds 8 bits, some numbers can’t just fit into one, and characters as a series.

• Stores program instructions for CPU to execute.
• Volatile- info is lost w/o power.

Permanent storage of programs and data. ie disk

Displays information. Resolution, dot pitch

NIC network interface card- connects computer to LAN.

Programming language- computer language- software

Primitive instructions (binary code). Very hard to read

Low level language, hard to read but not as hard as machine language. Uses ASSEMBLER

Like java or python. Human language, easiest to read

Source code/program.

Translates and executes one statement of source code into machine code in one step.

Translates entire source code into bytecode, then interpreter interprets and executes that into machine code. Two steps

Manage and control computer activity.

To develop and deploy apps on the internet for servers, desktop computers, and hand held devices

Java Standard edition (SE)- client based.

But there is Java enterprise edition (EE)- for servers and Micro edition (ME) - for mobile devices

Application Programmer interface. Usable features that provide functionality while programming

Java development kit. Software for creating, compiling, and debugging programs.

Java runtime environment. Necessary with JDK and includes JVM. Software that runs java programs

Software to create, edit, compile, debug, execute code, and test code

• Class
• Main method
• Statements
• Statement terminator
• Reserved words
• Comments
• Blocks

With single quotations ‘ ‘

Interprets byte code into machine code

Detected by compiler

Causes program to abort

Incorrect result

JDK. Source code compiled into bytecode by compiler (javac) and that bytecode is ran through JVM to produce result

• Read/analyze problem
• Design solution
• Code a solution
• Run code
• Test and debug

H

Built in data types (int double char)

Mix of language and code

Scanner name = new Scanner(System.in);

• Import scanner
• Create scanner object
• Prompt text
• Store value

= ... does not mean equality. Variable on left side.

Must be declared before giving value

Variables cannot be changed using final keyword. All caps, use underscore.

final double PI = 3.14159;

Use camelCase

CapitalizeFirstWord

• Byte- 8
• Short- 16
• Int- 32
• Long- 64
• Float- 32
• Double - 64

Can be letters string too. A number value that appears directly (ie. 34 with; int number = 34;)

• Addition- +=
• Mod - %=

Makes it so you don’t have to write variable name again (num = num + 8) = (num += 8)

• Requirement specification -user/designer talk
• System analysis- input process output (IPO)
• System design- IPO
• Implementation- translating design to programs
• Testing- requirements satisfied and no bugs
• Deployment- available to use
• Maintenance- changing and improving

• Undeclared/uninitializing/misspelling variables
• Integer overflow- using out of bounds values
• Round off errors- using floating point
• Integer division- won’t produce decimal
• Redundant input- creating 2 scanners

If writing an integer bigger than 2 billion (such as national debt) use long data type and append with “L”. (long num = 22L)

Float is less accurate (rounding off) and only necessary for looks. Append number like 100.4F or 100.4f

• Parenthesis
• Operators ( *, /, %) - if several left to right
• Addition subtraction

System.currentTimeMillis();

Should be able to read variable and answer with true or false

Expression has no semicolon , any code that evaluates to a result

Conditional statements based on Boolean expressions (Boolean hasValue = true) or (hasValue >= 0)

• If true - executes
• If false- blank

• If true- executes a block
• If falso- executes different block

• If
• If
• Else

• If score > 90
• A
• else if score > 80 b

boolean even = number % 2 == 0

• double randNum = Math.random()
• Scale it- randNum * 11 // values below 11
• Cast scaled number as integer // gets whole number

double randNum = (int)(Math.random() * 11);

• !- not
• &&- and
• || - or
• ^ - xor

It’s an if else that checks against a single quality. Don’t forget default means else

minVal = (a < b) ? a : b;

If a is less than b, assign a to minVal, else assign b

CPU is brain of computer and retrieve data from memory to use. In newer models, cpu and process at gigahertz levels of speed, which makes retrieving and using data when processing code faster

Programming languages allow us to talk to computers, but must be assembled into bytecode before they can be interpreted into machine code

Application programmer interface- provides usable features to improve overall functionality while in programming process

Integrated development environment- provides an environment that lets you create, edit, compile, debug, and execute code

Java development kit- encompasses tools needed to compile, debug, execute, and test code. Source code- bytecode- machine code

Java runtime environment- encompasses tools needed to interpret and execute code such as the JVM. Bytecode- machine code

To import functions that aren’t standard with the main method, they wrap around it

It’s the entry point for all programs

Can be used to point out errors and current values of variables so we can go value-by-value and determine if where there was a logic, syntax, or runtime error made

final int MAX_POSSIBLE_VALUE = 365;

Code compiles but terminated program execution abruptly with an error

Code does not compile