Unit 8 Vocabulary — The Keyboard: Part II

Noun (thing)
& (ampersand)
a symbol which is normally used to mean "and"
In SQL queries it is best practice to spell out 'AND' and not just use the ampersand (&) as a shortcut.
Noun (thing)
* (asterisk)
the character which often means "multiply" in a math equation or "match all" in a regular expression wildcard
The programmer could not remember whether to use an asterisk (*) or a percent sign (%) as a wildcard in his SQL regular expression.
Noun (thing)
@ (at sign)
the symbol often used in email addresses to separate usernames from domain names
The at sign key is often in very different locations on many international keyboards.
Noun (thing)
\ (back slash)
a character used to separate files and folders in Windows, and as an escape character in certain programming tasks
The user files were located in 'C:\documents and settings\gregbrady\my documents'.
Noun (thing)
{ } (brackets)
punctuation marks often used as control structures, or to denote variable interpolation
Brackets are also called "curly braces" and are used to define the beginning and end of code blocks, such as in functions or loops.
Noun (thing)
Case
in typography this is the distinction between capital (big) and minuscule (small) letters
In order to change case on a computer, the user typically presses the "Shift" key.
Noun (thing)
/ (forward slash)
a key used to separate folders and files, often used in Unix file systems
The user's php binary was located in /usr/local/php.
Noun (thing)
> (greater than sign)
the sign which means that the value on the right is less than the value on the left
5 > 3
Noun (thing)
< (less than sign)
the sign which means that the value on the left is smaller than the value on the right
3 < 5
Noun (thing)
- (minus sign)
the operator symbol often indicating the process of subtraction or difference
The program did not output the expected result because the programmer forgot a minus sign.
Noun (thing)
( ) (parentheses)
symbols used in pairs to group values or sets of values
Parentheses are often used to group values in an equation.
Noun (thing)
% (percent sign)
the symbol meant to show a common measurement based on a fraction of 100
The CEO reported that sales were up 75% over last quarter.
Noun (thing)
+ (plus sign)
the operator symbol, normally indicating addition
The elementary school teacher told the students that 2 + 2 = 4.
Noun (thing)
[ ] (square brackets)
symbols used in pairs to set apart or interject text within other text
In programming languages, the use of square brackets are sometimes used to show the elements of an array.
Noun (thing)
~ (tilde)
this key normally means "approximately" in mathematics; in Unix systems this character is used to represent a home directory
The student learned that his home directory was 'home/~johndoe' and his web directory was 'http://www.university.co.uk/students/johndoe'.
Noun (thing)
_ (underscore)
a character often used in file names to join words without using a space; originally used on typewriters to make underlined text
The long file name "hippy_dippy_string_concatenation.pl" contained many underscores because spaces aren't advised in Unix file names.