B
 
B*-tree (B star tree)
A tree in which only the leaf nodes contain data as well as keys. All other nodes contain only keys. See element, key, leaf, node, tree.
background color
The color in which the background of a graphic primitive is drawn.
backslash
The character \. This character is named <backslash> in the portable character set.
balance
(1) For audio, refers to the relative strength of the left and right channels. A balance level of 0 is left channel only. A balance level of 100 is right channel only. (2) A state of equilibrium, usually between treble and bass.
base class
In C++, a class from which other classes are derived through inheritance. A base class may itself be derived from another base class.
based on
To be implemented through another class. A new class is based on an existing class when the existing class is used to implement it.
basic source character set
In the C++ language, a set of 96 characters that can be used in a source file. The set consists of control characters, plus 91 graphical characters. Other characters can be added to source files through the use of universal character names. See character set, universal character set.
bidirectional language
A language that is written from right to left, but can contain strings that are written from left to right. Examples are Arabic and Hebrew, which have a right to left direction, but which can contain English text or numbers oriented in a left to right direction.
binary expression
An operation containing two operands and one operator.
binary stream
(1) An ordered sequence of untranslated characters. (2) A sequence of characters that corresponds on a one-to-one basis with the characters in the file. No character translation is performed on binary streams. IBM.
bit field
A member of a structure or union that contains a specified number of bits.
bit mask
A pattern of characters used to control the retention or elimination of portions of another pattern of characters.
block
(1) In programming languages, a compound statement that coincides with the scope of at least one of the declarations contained within it. A block may also specify storage allocation or segment programs for other purposes. I. (2) A string of data elements recorded or transmitted as a unit. The elements may be characters, words, or physical records. T. (3) The unit of data transmitted to and from a device. Each block contains one record, part of a record, or several records.
block statement
A group of data definitions, declarations, and statements that appear between a left brace { and a right brace } that are processed as a unit. IBM.
bookmark
In an application, a marker that points to a specified location to which the system returns when the marker is invoked..
boundary alignment
The position in main storage of a fixed-length field, such as halfword or doubleword, on an integral boundary for that unit of information. For example, a word boundary is a storage address evenly divisible by four. See alignment.
bounded collection
A collection that has an upper limit on the number of elements it can contain.
brackets
The characters [ (left bracket) and ] (right bracket), also known as square brackets. When used in the phrase "enclosed in (square) brackets" the symbol [ immediately precedes the object to be enclosed, and ] immediately follows it. When describing these characters in the portable character set, the names <left-bracket> and <right-bracket> are used. X/Open.
breakpoint
A marker in a program that signals the debugger to stop when execution reaches that point. Code beyond the breakpoint is not executed until further instructions are provided.
break statement
A language control statement that contains the keyword break and a semicolon. It is used to end an iterative or switch statement by exiting from it at any point other than the logical end. Control is passed to the first statement after the iteration or switch statement. See iteration, statement, switch statement.
buffer
(1) A routine or storage used to compensate for a difference in the rate of flow of data or in the time of occurrence of events when transferring data from one device to another. ANSI. (2) To allocate and schedule the use of buffers. ANSI.
buffer flush
A process that removes the contents of a buffer.
built-in function
A function that the compiler automatically puts inline instead of generating a call to the function. Also called a predefined function. Contrast with intrinsic function. IBM.
bundle
A group of graphic attributes to be used to render a graphic.
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