Operators - C++ Tutorials. Once introduced to variables and constants, we can begin to operate with them by using operators. What follows is a complete list of operators. At this point, it is likely not necessary to know all of them, but they are all listed here to also serve as reference.
Assignment operator (=). The assignment operator assigns a value to a variable. This statement assigns the integer value 5 to the variable x.
The and in (C) is a logical connective, since the truth of (C) is completely determined by (A) and (B): it would make no sense to affirm (A) and (B) but deny (C). You should remember that the logical operations ==, &&, and . If you have used a programming language such as C, you will. The Bitwise Operators Up: Operators Previous: The Unary Arithmetic Operators The Logical Operators Logical operators are mainly used to control program flow. Usually, you will find them as part of an if, a while, or some other control statement (Chapter 6) The.
The assignment operation always takes place from right to left, and never the other way around: This statement assigns to variable x the value contained in variable y. The value of x at the moment this statement is executed is lost and replaced by the value of y. Consider also that we are only assigning the value of y to x at the moment of the assignment operation.
Therefore, if y changes at a later moment, it will not affect the new value taken by x. For example, let's have a look at the following code - I have included the evolution of the content stored in the variables as comments: 1. Notice how a was not affected by the final modification of b, even though we declared a = b earlier. Assignment operations are expressions that can be evaluated. That means that the assignment itself has a value, and - for fundamental types- this value is the one assigned in the operation. For example: In this expression, y is assigned the result of adding 2 and the value of another assignment expression (which has itself a value of 5).
It is roughly equivalent to: With the final result of assigning 7 to y. The following expression is also valid in C++: It assigns 5 to the all three variables: x, y and z; always from right- to- left. Arithmetic operators ( +, - , *, /, % ). The five arithmetical operations supported by C++ are: operatordescription+addition- subtraction*multiplication/division%modulo. Operations of addition, subtraction, multiplication and division correspond literally to their respective mathematical operators. The last one, modulo operator, represented by a percentage sign (%), gives the remainder of a division of two values. For example: results in variable x containing the value 2, since dividing 1.
Compound assignment (+=, - =, *=, /=, %=, > > =, < < =, & =, ^=, . They are equivalent to assigning the result of an operation to the first operand: expressionequivalent to.. For example: 1. 23. They are equivalent to +=1 and to - =1, respectively. Thus: are all equivalent in its functionality; the three of them increase by one the value of x.
In the early C compilers, the three previous expressions may have produced different executable code depending on which one was used. Nowadays, this type of code optimization is generally performed automatically by the compiler, thus the three expressions should produce exactly the same executable code.
A peculiarity of this operator is that it can be used both as a prefix and as a suffix. That means that it can be written either before the variable name (++x) or after it (x++). Although in simple expressions like x++ or ++x, both have exactly the same meaning; in other expressions in which the result of the increment or decrement operation is evaluated, they may have an important difference in their meaning: In the case that the increase operator is used as a prefix (++x) of the value, the expression evaluates to the final value of x, once it is already increased. On the other hand, in case that it is used as a suffix (x++), the value is also increased, but the expression evaluates to the value that x had before being increased.
Circle c = new Circle(32); object o = c; int i = (int)o; // it compiles okay but throws an exception at runtime. C# provides two more very useful operators that can help us to perform casting in a much more elegant manner by using the 'is' and 'as' operators. Logical Operators in C - Learn ANSI, GNU and K/R standard of C programming language with simple and easy examples covering basic C, language basics, literals, data types, functions, loops, arrays, pointers, structures, input and output, memory management. The output of this program is 5 can anybody expalian the logic behind it Sarim . Logical Operators (&&, ? Well i had a test in my college on C programming and i had to answer the Void main. C programming language provides several operators to perform different kind to operations. There are operators for assignment, arithmetic functions, logical functions and many more. These operators generally work on many types of variables or constants, though.
Logical operators are usually used with conditional statements which we shall meet in the next Chapter. The two basic logical operators are: && for logical AND, Facebook - https://www.facebook.com/TheNewBoston. GitHub - https://github.com/buckyroberts Google+ - https://plus.google.com/+BuckyRoberts LinkedIn - https://www.linkedin.com/in/buckyroberts reddit - https://www.reddit.com/r/thenewboston/ Support - https://www.patreon.com/thenewboston thenewboston - https://thenewboston.
Notice the difference: Example 1. Example 2. x = 3; y = ++x; // x contains 4, y contains 4. In Example 1, the value assigned to y is the value of x after being increased. While in Example 2, it is the value x had before being increased. Relational and comparison operators ( ==, !=, > , < , > =, < = ). Two expressions can be compared using relational and equality operators.
For example, to know if two values are equal or if one is greater than the other. The result of such an operation is either true or false (i. Boolean value). The relational operators in C++ are: operatordescription==Equal to!=Not equal to< Less than> Greater than< =Less than or equal to> =Greater than or equal to. Here there are some examples: 1.
Of course, it's not just numeric constants that can be compared, but just any value, including, of course, variables. Suppose that a=2, b=3 and c=6, then: 1. Be careful! The assignment operator (operator =, with one equal sign) is not the same as the equality comparison operator (operator ==, with two equal signs); the first one (=) assigns the value on the right- hand to the variable on its left, while the other (==) compares whether the values on both sides of the operator are equal. Therefore, in the last expression ((b=2) == a), we first assigned the value 2 to b and then we compared it to a (that also stores the value 2), yielding true. Logical operators ( !, & & , ! It has only one operand, to its right, and inverts it, producing false if its operand is true, and true if its operand is false.
Basically, it returns the opposite Boolean value of evaluating its operand. For example: 1. 23. The logical operators & & and . The operator & & corresponds to the Boolean logical operation AND, which yields true if both its operands are true, and false otherwise.
The following panel shows the result of operator & & evaluating the expression a& & b: & & OPERATOR (and)aba & & btruetruetruetruefalsefalsefalsetruefalsefalsefalsefalse. The operator . Here are the possible results of a. Therefore, in the last example ((5==5). This is known as short- circuit evaluation, and works like this for these operators: operatorshort- circuit& & if the left- hand side expression is false, the combined result is false (the right- hand side expression is never evaluated).? Its syntax is: condition ? When the set of expressions has to be evaluated for a value, only the right- most expression is considered.
For example, the following code: would first assign the value 3 to b, and then assign b+2 to variable a. So, at the end, variable a would contain the value 5 while variable b would contain value 3. Bitwise operators ( & , . There are several ways to do this in C++. The simplest one, which has been inherited from the C language, is to precede the expression to be converted by the new type enclosed between parentheses (()): 1. The previous code converts the floating- point number 3. Here, the typecasting operator was (int).
Another way to do the same thing in C++ is to use the functional notation preceding the expression to be converted by the type and enclosing the expression between parentheses: Both ways of casting types are valid in C++. This operator accepts one parameter, which can be either a type or a variable, and returns the size in bytes of that type or object: Here, x is assigned the value 1, because char is a type with a size of one byte. The value returned by sizeof is a compile- time constant, so it is always determined before program execution. Other operators. Later in these tutorials, we will see a few more operators, like the ones referring to pointers or the specifics for object- oriented programming. Precedence of operators. A single expression may have multiple operators.
For example: In C++, the above expression always assigns 6 to variable x, because the % operator has a higher precedence than the + operator, and is always evaluated before. Parts of the expressions can be enclosed in parenthesis to override this precedence order, or to make explicitly clear the intended effect. Notice the difference: 1.
From greatest to smallest priority, C++ operators are evaluated in the following order: Level. Precedence group. Operator. Description.
Grouping. 1Scope: :scope qualifier. Left- to- right. 2Postfix (unary)++ - -postfix increment / decrement. Left- to- right()functional forms.