Question

This clears (writes a 0 to) a bit of a numeric variable. Which of the following is used for this purpose?

1) bitClear
2) sizeof()
3) pinMode
4) #include

Answer 1

The function used to clear a single bit of a numeric variable is called bitClear, which is commonly used in environments like Arduino to manage individual bits for controlling digital pins or modifying control registers.

Step-by-step explanation:

The function used to clear (write a 0 to) a single bit of a numeric variable in many programming environments is bitClear. The bitClear function is typically used with microcontrollers, such as those in the Arduino platform, to manipulate individual bits of a number, which can be particularly useful when setting the values of control registers or managing the states of digital pins. The syntax generally involves specifying the variable and the bit position to be cleared. The use of sizeof() would return the size of a variable or data type, pinMode is used to set the mode of a digital pin on microcontrollers, and #include is a preprocessor directive used to include files in a program.

To clear a bit using bitClear, you typically perform a bitwise AND operation with the complement of a bit mask that has a 1 only in the position of the bit you want to clear. For example, to clear the third bit (bit position 2, if counting from 0) of an integer variable named myVar, you might use a code snippet like this:

bitClear(myVar, 2);

This operation results in setting the third bit to 0, without changing the other bits of myVar.