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33 Cards in this Set
- Front
- Back
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What are some historical points about C++?
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Designed and implemented byBjarne Stroustrup. A super set of C. Originally called C with classes (1980).
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C++ is designed to...
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...be a statically typed, general-purpose language that is as efficient and portable as C, support multiple programming styles, function without a sophisticated programming environment, and a zero-overhead principle
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Describe the structure of a program
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Comments
preprocessor directives using directives Block of code { comments statements } |
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Here is an example of a program
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/* Simple C++ Program */
/* This program computes the */ /* distance between two points. */ #include <iostream> // Required for cout, endl. #include <cmath> // Required for sqrt() using namespace std; int main() { // Declare and initialize objects. double x1(1), y1(5), x2(4), y2(7), side1, side2, distance; // Compute sides of a right triangle. side1 = x2 - x1; side2 = y2 - y1; distance = sqrt(side1*side1 + side2*side2); // Print distance. cout << "The distance between the two points is " << distance << endl; // Exit program. return 0; } |
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What are comments?
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Comments help people read programs, but are ignored by the compiler.
Comments are optional. In C++ there are two types of comments. Line comments begin with // and continue for the rest of the line. Delimited comments begin with /* and end with */ |
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What are preprocessor directives?
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Provide instructions to the compiler that are performed before the program is compiled.
Begin with a # Example: #include <iostream> The #include directive instructs the compiler to include statements from the file iostream. |
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What is the using directive?
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The using directive instructs the compiler to use files defined a specified namespace.
Example: using namespace std; std is the name of the Standard C++ namespace. Otherwise you need to write std::cin, std::cout, std::endl |
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What is a C fashion header file?
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Some old compilers do not support namespace.
Omit using directive Instead write #include <iostream.h> #include <math.h> (include a “.h”) Header file: includes declarations of function, variables, classes, etc. Source codes are in another file (.c .cc .cpp). Separate interface from implementation |
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What is a block of code?
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A block of code is defined by a set of curly braces {…}. Every C++ problem solution contains exactly one function named main(). C++ program solutions always begin execution in main()
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What is the main function?
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The main function contains two types of commands: declarations and statements.
Indentation and blank lines are not required, but they are needed for readability. Note that all C++ statements are required to end with a semicolon. The statement return(0) returns the control to the operating system. |
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What are constants and variables?
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Constants and variables represent memory locations that we reference in our program solutions.
Constants are objects that store specific data that can not be modified. 10 is an integer constant 4.5 is a floating point constant "Side1" is a string constant 'a' is a character constant Variables are memory locations that store values that can be modified. double x1(1.0), x2(4.5), side1; side1 = x2 - x1; x1, x2 and side1 are examples of variables that can be modified. |
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What are symbolic constants?
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A symbolic constant is defined in a declaration statement using the modifier const.
Ex. const double pi(3.14); or #define pi 3.14; A symbolic constant allocates memory for an object that can not be modified during execution of the program. Any attempt to modify a constant will be flagged as a syntax error by the compiler. A symbolic constant must be initialized in the declaration statement. Note: the cmath (math.h) library includes many mathematical constants. |
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What are memory snapshots?
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Memory snapshot: shows the content of a memory location at a specified point in the execution of the program.
Variables uninitialized will have values unpredictable (another program can take that memory space and insert any values into it). int x, y (1), z; z = x + y; z = ? |
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What are some common C++ data types?
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Keyword, Example of a constant
bool, true char, '5' int, 25 double, 25.0 string, "hello" //#include<string> |
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What are identifiers?
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Identifiers are used to name objects in C++.
Rules for selecting valid identifiers: Identifier must begin with a letter or underscore _ Identifiers consists of alphanumeric characters and underscore character only. An identifier cannot be a reserved word. Only the first 31 characters of an identifier are used to distinguish it from other identifiers. C++ is case sensitive. Thus, Side1 and side1 are unique identifiers that represent different objects. |
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What are declarations?
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A type declaration statement defines new identifiers and allocates memory (type specifier).
An initial value may be assigned to a memory location at the time an identifier is defined. Syntax: [modifier] data_type identifier_list; Examples: double length( 20.75), width(11.5), volume; int numberOfFeetInYard(3); const int MIN_SIZE = 0; |
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What is an assignment statement?
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The assignment operator (=) is used in C++ to assign a value to a memory location.
The assignment statement: x1 = 1.0; assigns the value 1.0 to the variable x1. Thus, the value 1.0 is stored in the memory location associated with the identifier x1. Example int x, y, z; x=y=0; z=2; |
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What is scientific notation?
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Floating point: can present both integer and non-integer values, such as 2.5, -0.004.
A floating point value expressed in scientific notation: expressed as a mantissa times a power of 10. Mantissa part must be between 1.0 and 10.0. Exponential notation: 256.1 = 2.561 * 10^2 -0.004 = -4.0e-3 |
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Are there restrictions on data types?
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Yes, such as short, int, long, float, double, and long double.
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What are the main arithmetic operators?
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Addition +
Subtraction - Multiplication * Division / Modulus % Modulus returns remainder of division between two integers Example 5 % 2 returns a value of 1 Note: 5/2 returns 2 but 5.0/2.0 returns 2.5 |
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What is the cast operator?
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The cast operator is a unary operator that requests that the value of the operand be cast, or changed, to a new type for the next computation. The type of the operand is not affected.
Example: int count(10), sum(55); double average; average = (double)sum/count; |
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What is the precedence of arithmetic and assignment operators?
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1. Parentheses, innermost first
2. Unary operators (+ - ++ __), right to left 3. Binary operators (* / %), left to right 4. Binary operators (+ -), left to right 5. Assignment operators (= += -= *= /= %=), right to left |
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Describe overflow and underflow
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Overflow: answer too large to store
Example: using 16 bits for integers result = 32000 +532; Exponent overflow: answer’s exponent is too large Example: using float, with exponent range –38 to 38 result = 3.25e28 * 1.0e15; Exponent underflow: answer’s exponent too small Example: using float, with exponent range –38 to 38 result = 3.25e-28 *1.0e-15; |
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What are the increment and decrement operators?
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ncrement Operator ++
post increment x++; pre increment ++x; Decrement Operator - - post decrement x- -; pre decrement - -x; Assume k = 5 prior to executing the statement. m= ++k; both m and k become 6 n = k- -; n becomes 5 and k becomes 4 w = ++x –y; w = x++ - y; |
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What are some abbreviated assignment operators?
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operator example equivalent statement
+= x+=2; x=x+2; -= x-=2; x=x-2; *= x*=y; x=x*y; /= x/=y; x=x/y; %= x%=y; x=x%y; |
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What is the standard input and output stream?
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cin is an istream object defined in the header file iostream
cin is defined to stream data from standard input (the keyboard) We use the input operator >> with cin to assign values to variables General Form: cin >> identifier >> identifier; cout is an ostream object defined in the header file iostream cout is defined to stream data from standard input (the keyboard) We use the input operator << with cout to assign values to variables General Form: cout >> identifier >> identifier; |
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What are some Manipulators and Methods for i/o stream?
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endl – places a newline character in the output buffer and flushes the buffer.
setf() and unsetf() to set the following modes ios::showpoint display the decimal point ios::fixed fixed decimal notation ios::scientific scientific notation ios::right right justification ios::left left justification |
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What are the <cmath> trigonometric functions?
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cos Compute cosine
sin Compute sine tan Compute tangent acos Compute arc cosine asin Compute arc sine atan Compute arc tangent atan2 Compute arc tangent with two parameters |
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What are the <cmath> hyperbolic functions?
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cosh Compute hyperbolic cosine
sinh Compute hyperbolic sine tanh Compute hyperbolic tangent |
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What are the <cmath> exponential and logarithmic functions?
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exp Compute exponential function
frexp Get significand and exponent ldexp Generate number from significand and exponent log Compute natural logarithm log10 Compute common logarithm modf Break into fractional and integral parts |
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What are the <cmath> power functions?
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pow Raise to power
sqrt Compute square root |
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What are the <cmath> rounding, absolute value and remainder functions?
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ceil Round up value
fabs Compute absolute value floor Round down value fmod Compute remainder of division |
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What are some common <cctype> functions?
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isalnum Check if character is alphanumeric
isalpha Check if character is alphabetic) iscntrl Check if character is a control character isdigit Check if character is decimal digit isgraph Check if character has graphical representation using locale islower Check if character is lowercase letter isprint Check if character is printable ispunct Check if character is a punctuation character isspace Check if character is a white-space isupper Check if character is uppercase letter isxdigit Check if character is hexadecimal digit |
