I: Introduction (1-2 sentences)
A: A computer program is a sequence of instructions, which is used to give computers the ability to do things automatically.
II: Body (3-4 paragraphs)
A: An instruction is a command for the computer to do something, such as add 2 numbers or draw a shape or display text on the screen. Instructions are written in programming languages, which are like natural languages except that they tell the computer what to do instead of people.
B: A programming language is a set of words and symbols that humans use to communicate with machines.
C: Programming languages are designed to be easy for humans to read, write, and understand.
D: A programming language consists of vocabulary, syntax, and semantics. The vocabulary is the set of programming terms that are available for writing programs. Syntax is the set of rules that determines how the vocabulary may be combined into statements. Semantics is the set of rules that determine what each statement means.
E: The vocabulary of a language includes words, special characters, punctuation marks, and other symbols. It also includes reserved words, which are words that have special meanings to the compiler.
F: C# has five different types of variables: integer, long integer, float, double, and string. These are called primitive data types. You can declare variables using these data types. You can also define your own data types by creating class definitions. Variables are stored in memory. A variable can contain any value that matches its data type. For example, an integer variable can contain any integer value, but not a floating-point number or a string.
III: Conclusion (1-2 sentences)
G: Computers must follow fixed rules when they execute programs. If you break these rules, your program won’t work correctly. This is called an error. Although it’s possible to write programs with no errors at all, it’s not always possible to test every line of code for correctness before giving it to users or clients. Instead, many software developers rely on compilers to catch errors. A compiler is a program that translates high-level language programs into machine language programs. Compilers check for common errors; however, they may miss some errors because compilers are not perfect. Programmers can make compilers even better by finding and reporting new errors in their compilers so that compilers can be updated with additional error checks.