Download Scripting and Programming - Foundations - C173, Exam Review, latest update. VERIFIED. and more Exams Programming Methodologies in PDF only on Docsity!
Scripting and Programming -
Foundations - C173, Exam Review, latest
update. VERIFIED.
Program instructions executing one at a time Input A program gets data, perhaps from a file, keyboard, touchscreen, network, etc. Process A program performs computations on that data, such as adding two values like x + y. Output A program puts that data somewhere, such as to a file, screen, network, etc. Variable In a program, a name that can hold a value. Refer to data, like x, y, and z. The value is "varying" as a program assigns a variable like x with new values. Computational Thinking A method of problem-solving that helps computer scientists prepare problems for digital solutions Algorithm a sequence of instructions that solves a problem flowchart A graphical language for creating computer programs A diagram that shows step-by-step progression through a procedure or system especially using connecting lines and a set of conventional symbols. A program is a list of statements that carry out actions to accomplish a task in a computer program Interpreter Converts a program written in a higher level language into a lower level language and executes it, beginning execution before converting the entire program.
The interpreter carries out each program statement's action, getting input values as needed, and generating output as well. Incidentally, the interpreter is itself a program. Program execution begins at the start node. A statement executes sequentially (one at a time.) Run the act of carrying out each action's statement. Statement A specific action that the interpreter should carry out, such as get a value from input into a variable, assign a variable with a value, or put a value to the output. String Literal text in double quotes Character Any letter (a-z, A-Z), digit (0-9), or symbol (~, !, @, etc.) Cursor indicates where the next output item will be placed in the output. The system automatically moves the cursor after the previously-output item. Newline /n to make a new line Invisible in the output Comment text a programmer adds to a program, to be read by humans to better understand the code, but ignored by the program when executing Starts with // and includes all the subsequent text on that line Whitespace blank spaces (space and tab characters) between items within a statement, and to newlines A common practice is to use exactly one space
A standard code for representing text characters using one byte. Generally replaced by UTF-8 or UTF- 16 to support international languages. Unicode another character encoding standard, published in 1991, whose codes can have more bits than ASCII and thus can represent over 100,000 items, such as symbols and non-English characters. What is the 7-bit code for lower-case, "a"? 1100001 What is the 7-bit code for lower-case, "A"? 1000001 decimal numbers the base ten numbers. binary numbers Number system with a base of 2. They are preferred for computers for precision and economy. Pseudocode Informal textual description of a program, where each line represents a statement in a human-readable format that is not meant for machines to read and execute. Assignment Statement an instruction that assigns a value to something, such as to the property of an object, assigns a variable with a value. Does not mean it is equal to the value, the variable gets assigned that value. Expression A mathematical phrase that contains operations, numbers, and/or variables. Identifier name created by a programmer for an item like a variable or function An identifier must: be a sequence of letters (a-z, A-Z), underscores (_), and digits (0-9) start with a letter or underscore Reserved Word A word in a language that has special meaning; it cannot be used as an identifier Naming conventions 2020: A set of style guidelines defined by a company, team, teacher, etc., for naming variables.
ex: Lower camel case numApps Underscore separated. people_here Literal a specific value in code, like 2. Operator a symbol that performs a built-in calculation, addition + | subtraction & negation - | multiplication * | division / Expression vs. Assignment (expression) x + 1 | (assignment) y = x + 1 Evaluates replacing an expression ex: x = 5 ---> x + 1 = 6 (x has evaluated to 6) Precedence Rules PEMDAS Parentheses Unary - (negation) Multiplication & Division Addition & Subtraction ALL LEFT TO RIGHT, IF THE PRECEDENCE IS EQUAL. Good practice is to use parentheses to make order of evaluation explicit, rather than relying on precedence rules as in: y = (m * x) + b, unless order doesn't matter as in x + y + z. incremental development The process of writing, compiling, and testing a small amount of code, then writing, compiling, and testing a small amount more (an incremental amount), and so on. floating point numbers real numbers with a decimal point floating-point literal
