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C++ Unary Operators

    The unary operators take a single argument in C++ language. Some of the operators you have already seen in previous articles are unary operators.

    Here is the list of unary operators.

    Unary OperatorsDescription
    *Dereference operator
    &Address Of operator
    Minus sign
    !Not  operator
    ~Complement
    ++Increment operator
    Decrement operator
    typeForced type conversion
    sizeofSize of the data type
    Table 1 – Unary Operators

    Dereference Operator (*)

    When a C++ pointer type is declared, and it is pointing to a variable. The dereference operator helps to access the content of a pointer type. We will learn more about while discussing pointers.

    Address Of Operator (&)

    It resembles the bitwise AND, but when used as a unary operator it returns the address of the variable.

    int A = &B;

    The variable A will store address of the variable B, not its value.

    Minus Sign (-)

    Minus is an arithmetic operator, but as a unary operator, it is used to denote a negative value. It is most commonly used the unary operator in C++ programs.

    Negation Operator(!)

    The negation is a logical operator which negates the value of a boolean variable. If the value is 1 (true) then, it becomes 0 (false). If the value is 0 (false) then, it becomes 1 (true).

    Bitwise Complement (~)

    The bitwise complement modifies the binary value of a variable to 2‘s complement binary value. In other words, you get a negative value for a positive number plus 1.

    \begin{aligned}p = 45  \hspace{5px} becomes \hspace{5px} -46 \hspace{5px} after \hspace{5px} \sim p.\end{aligned}

    Increment Operator (++)

    The increment operator is used in loop structures. You will learn about loop structures later in this C++ tutorial. The increment operator increments an associated variable by 1.

    i = 12;
    i++; // same as saying i = i + 1;

    The value of i after increment is 13.

    Decrement Operator (–)

    The decrement operator decreases the associated variable value by 1.

    i = 34;
    i--;

    The value will be 33 after decrement.

    Type Operator

    The type conversion operator is used to modify the data type of a variable by force. The initial data type is changed to what specified in the type operator. It is also known as cast operator.

    int A;
    A = 10;
    (float) A;

    This will change the variable A into floating type from an integer.

    Sizeof Operator( sizeof)

    The sizeof operator is a special operator that returns the size of the data type in C++ program.

    int A;
    sizeof(A);

    This will return the size of integer data type which is 4 bytes.