Computer Applications (Commerce) – XII Chapter 3 Functions

A set of vocabulary flashcards covering the core concepts of programming functions, predefined C++ library functions, and user-defined function parameters.

Modularisation

The process of breaking large programs into smaller sub programs.

Functions

A named unit of statements in a program to perform a specific task, which can be predefined or user-defined.

Parameters (Arguments)

The data required for performing the task given to the function, provided within a pair of parentheses.

Value returned

The result given by a function after performing its task; a function can return only one value or no value.

Predefined functions

Ready-to-use functions available in header files that must be included to use them.

getchar()

A console function in cstdio or stdio.h used to input a character.

putchar()

A console function in cstdio or stdio.h used to display a character.

get()

A stream function in iostream used to input a character or a string of a specific maximum length.

getline()

A stream function in iostream used to input a string of a specified maximum length.

put()

A stream function in iostream used to display a character.

write()

A stream function in iostream used to display a string of a specified maximum length.

strlen()

A string function in cstring or string.h used to find the length of a string.

strcpy()

A string function in cstring or string.h used to copy one string into another.

strcat()

A string function in cstring or string.h used to append (concatenate) one string to another.

strcmp()

A string function that compares two strings; returns 0 if they are the same, a negative value if the first is lower, and a positive value if the first is higher.

strcmpi()

A string function that compares two strings while ignoring the case of the characters.

abs()

A mathematical function in cmath or math.h used to find the absolute value of an integer.

fabs()

A mathematical function in cmath or math.h used to find the absolute value of a floating point number.

sqrt()

A mathematical function in cmath or math.h used to find the square root of a number.

pow()

A mathematical function that takes two arguments $x$ and $y$ and returns the value of $x^y$.

isupper()

A character function that returns non-zero if a character is in upper case and 0 otherwise.

islower()

A character function that returns non-zero if a character is in lower case and 0 otherwise.

isalpha()

A character function that returns non-zero if a given character is an alphabet and 0 otherwise.

isdigit()

A character function that returns non-zero if a character is a digit and 0 otherwise.

isalnum()

A character function that returns non-zero if a character is alphanumeric and 0 otherwise.

toupper()

A character function used to convert a given character into its uppercase equivalent.

tolower()

A character function used to convert a given character into its lowercase equivalent.

Function Prototype

The declaration of a function that provides the compiler with names, return types, number and type of arguments, and accessibility.

Formal arguments

The variables used in the function definition as arguments to receive values.

Actual (original) arguments

The constants, variables, or expressions used in the function call to pass values.

Default arguments

Formal arguments that are initialized with values within the function declaration or definition.