isnumber

isnumber(expr)

Determines whether the expression expr is a normal numeric value

The function of checking the usual numeric value of a variable in programming is an important component to ensure proper data processing. This function allows the programmer to verify that the value of a variable is indeed a number and can be safely used in further code.

To check the usual numeric value of a variable, you can use the following algorithm:

1. Check whether the value of the variable is a number.

- If the value of the variable is not a number, then the function must return the boolean value "false" and stop further code execution.

- If the value of the variable is a number, then the function can continue further checking.

2. Check whether the value of the variable is an integer or a decimal fraction.

- If the value of the variable contains a decimal point or an exponential notation, then the function must return the boolean value "false" and stop further code execution.

- If the value of the variable does not contain a decimal point and does not have an exponential notation, then the function can continue further verification.

3. Check whether the value of the variable is in the acceptable range of numeric values (you can write an additional function for this).

- If the value of the variable is in the acceptable range, then the function must return the boolean value "true". The acceptable range of numeric values can be set according to the requirements and limitations of a specific task.

- If the value of the variable is not in the acceptable range, then the function must return the boolean value "false".

The described algorithm allows you to check whether the value of a variable is an ordinary numeric value. This is important for creating reliable and secure program code that takes into account possible errors and exceptional situations when working with numeric data.