Chapter 1. Flashcards
what’s another name for a program?
Another name for a program (or part of a program) is code.
what are the two important qualities about a programmer?
They know how to break big problems into smaller, step-by-step procedures & they can express these steps in a very precise language.
what is a language called that involves writing steps?
A language for writing steps is called a programming language.
how many programming languages besides Java?
Java is just one of several thousand useful programming languages.
how is it different and similar between different programming languages?
Computer languages can be very different from one another, but in some ways, they’re all the same.
how would you explain the similarity of one language to another?
It’s just a mental substitution of one set of symbols for another.
how do programmers learn so many languages seemingly so easily?
Eventually, writing in different languages becomes second nature as they are the same just written differently. it’s just a mental substitution of a set of symbols for another.
what process happens when you create a new computer program?
When you create a new computer program, you go through a multistep process. First you create source code which gets interpreted by the compiler which turns into bytecode which is interpreted by the jvm which gets converted into ones and zeros and then the computer interprets those 1s and 0s to run the program.
what is a compiler?
Compiler: A compiler translates your source code into byte code
what is a virtual machine?
the virtual machine (jvm) interprets the bytecode and converts it into machine code 1s & 0s for the computer to understand
what is an API?
Application programming interface: An application programming interface contains useful prewritten code.
what tools are involved in the multi step process for creating a computer program?
The process involves three important tools: compiler, virtual machine, and an API
how do computer circuits interact with letters of the alphabet to create words?
computer circuits don’t deal directly with letters of the alphabet. When you see the word Start on your computer screen, the computer stores the word internally as a collection of 1s and 0s
what is the correct way to understand a 5 letter word on your computer?
seeing a friendly looking five-letter word is your interpretation of the computer screen’s pixels, and nothing more.
how does a computer’s complicated codes of 1s and 0s become understable to humans?
Computers break everything down into very low-level, unfriendly sequences of zeros and ones and then put things back together so that humans can deal with the results.
how do you get the computer to understand your written code?
the program has to be interpreted and converted into zeros and ones.
what is the name of the process which translates a programmers written code to be understood by the computer?
The official name for the translation process is compilation.
if you wrote code without compilation and ran the code, what is the result?
Without compilation, the computer can’t run your program.
what is the name of the codes of the challenging mess of 1s & 0s ?
The compiled mumbo jumbo of 1s & 0s goes by many different names: Most Java programmers call it machine code
what is bytcode often called and why?
It’s often called a .class file. That’s because, in Java, the bytecode gets stored in files named SomethingOrOther.class
what are the names and the differences between a programmer’s written code and the 1s & 0s the computer translates
To emphasize the difference, Java programmers call the part they write for code, the source code and refer to the zeros and ones that are converted by the jvm from the bytecode ,machine code.
how can a programmer create bytecode?
a process of a tool called the compiler is used to interpret and convert your written code which is source code into bytecode
what is the name of the tool used to convert source code into bytecode?
To create bytecode, the computer uses a special software tool called a compiler
what type of code is compiled to create another type of code & what type of code is the result once it is compiled?
The computer compiles source code to create bytecode.
what is the name of the file which contains a special software tool used for converting source code into object code?
Your computer’s hard drive may have a file named javac or javac.exe. This file contains that special software tool — the compiler.
what does the word javac stand for?
The word javac stands for Java compiler
what type of file is used when running instructions to create bytecode?
new object code is created by going behind the scenes and running the instructions in the javac file.
what is usually mistaken as the relationship between bytecode and source code?
a bytecode file is not a cryptogram substituting 1s & 0s in keywords like “if” & “else”, it’s the encoding of a program’s logic.
what do 1s & 0s describe to your computer?
the 1s & 0s describe the flow of data from one part of your computer to another.