Write four arithmetic operations for elementary school students in C!

It's all as simple as that, have you ever learned C!

Please give a clear answer first: because the program stipulates that you enter an operator first, followed by two operands.

Explain why: Please see the ** section below.

The first scanf("%c",&oper);This sentence asks for a (note that it is) value in character format, given to the oper;

If you enter a number, English, etc., if you enter 10 first, then the oper is 1, not 10, because %c can only read one character at a time;

Next, enter the second and third, and the program will judge the oper further down, if the oper is equal to the - sign, it will perform subtraction, and if it is equal to the + sign, it will execute the addition;

So if you enter an operand that doesn't match any operator, you can't do the operation.

Is there a solution:

Reverse the order of the statements: copy the first printf line and the first scanf line, note that the two printf lines are above the scanf, and put these two sentences after the second scanf and before the third print. You can enter 1 space + 2 space enter, and that's it.

When the program runs, you'll be prompted first for an operator, and then for an operand. If you don't follow the prompts, of course the program will report an error.

Here's a complete program, I tested it to meet your requirements, you're looking at it, I wrote a modular implementation, and I posted you a bit messy, and the function declaration if in one. The c file puts all the subfunctions in front of the declaration, which is not very complicated, include

#include

#include ""Self-defined must be enclosed in double quotation marks.

If you use angle brackets, you will make an error.

Included here. h file.

Function function: Realize subtraction, addition, multiplication and division.

void main()

elseprintf("Typo error re-entered")}}

#include

#include

void division(float a,float b)

#include

#include

void multiplication(float a,float b)

#include

#include

void subtraction(float a,float b)

#include

#include

void sum(float a,float b)

For example, if you define an integer variable and assign the value a=3, the value of a will be 4 after executing a++, and if ++a is the current value of a, it will only increase after a participates in the operation.

First, if -- in the same way, change the self-increase to self-subtraction