I was do manual analysis to this code. Would wait that the value of variable D change to 1 after first call to F1 function, but conserve his value on 2.
Also i noticed that comment or not comment the *Y--; has no effect.
The output is:
8 9 5 2
5 9 5 2
15 13 4 2
5 13 4 2
Shouldn't variable D change your value to 1 after the first print?
#include <stdio.h>
int F1 (int, int *);
int A = 3;
int B = 7;
int C = 4;
int D = 2;
void main(void)
{
A = F1 (C, &D);
printf("\n %d %d %d %d", A, B, C, D);
C = 3;
C = F1(A, &C);
printf("\n %d %d %d %d", A, B, C, D);
}
int F1 (int X, int *Y)
{
int A;
A = X * *Y;
C++;
B += *Y;
printf ("\n %d %d %d %d", A, B, C, D);
*Y--;
return(C);
}
It's a precedence issue.
*Y--;
means
*(Y--);
but you want
(*Y)--;
Related
#include<stdio.h>
int add(int, int); // function prototype
int main()
{
int a, b;
// printf("Enter 2 integer numbers\n");
// scanf("%d%d", &a, &b);
//function call add(a, b);
printf(" %d + %d = %d \n", a, b, add(2, 7));
Please focus on this line why it gives address + 0 = 9//
return 0;
}
//function definition
int add(int x, int y)
{
return x+y;
}
// produces outPut : 199164000 + 0 = 9
You commented the scanf function and also didn't given values for the a and b. So it printed garbage values. You also need to pass a and b into the add(a,b) function.
#include<stdio.h>
int add(int, int); // function prototype
int main()
{
int a, b;
// printf("Enter 2 integer numbers\n");
scanf("%d%d", &a, &b);
//function call add(a, b);
printf(" %d + %d = %d \n", a, b, add(a, b));
return 0;
}
//function definition
int add(int x, int y)
{
return x+y;
}
It is not printing any address. It is printing garbage values. You have not given any values to the variable a and b. So it will print garbage values. Why you commented scanf statement. Just stop commenting it and it will work.
I am getting the following error while executing code on Visual Studio 2019
MSB6006"CL.exe" exited with code 2
#include<stdio.h>
#include<conio.h>
int main()
{
int a, b, c,x;
x = a / (b - c);
printf("\n Enter values of a,b and c");
scanf_s("%d%d%d", &a, &b, &c);
printf("\n The value of x is %d", x);
return 0;
}
Your order of statements is off.
First assign values to a, b, and c.
Only after use those values in calculations.
#include <stdio.h>
int main(void) {
int a, b, c, x;
// x = a / (b - c); // NOPE! a, b, and c have no valid values
printf("Enter values of a, b and c\n");
scanf("%d%d%d", &a, &b, &c);
x = a / (b - c); // calculation moved here; a, b, and c (hopefully) have valid values now
printf("The value of x is %d\n", x);
return 0;
}
Note: the return value of scanf() should be checked to be sure all of a, b, and c have valid values.
if (scanf("%d%d%d", &a, &b, &c) != 3) /* error */;
Note 2: I changed your code a little bit: removed non-standard <conio.h>, changed the placing of most '\n' to be more line-oriented, replaced the optional scanf_s (this function may not exist in all C11/C18 implementations).
//Enter a 4-digit integer n from the keyboard, and write a program to divide it into two 2-digit integers a and B. Calculate and output the results of the addition, subtraction, multiplication, division and redundancy operations of the split two numbers. For example, n=-4321, if the two integers after splitting are a and b, then a=-43 and b=-21. The result of division operation requires that it be precise to 2 decimal places, and the data type is float. Redundancy and division operations need to take into account the division of 0, that is, if the split B = 0, then output the prompt information "The second operator is zero!"
//Failure to pass the test，how should i fix
#include<stdio.h>
#include<math.h>
int main()
{
int x, a, b;
printf("Please input n:\n");
scanf("%d", &x);
a = x / 100;
b = x % 100;
printf("%d,%d\n", a, b);
printf("sum=%d,sub=%d,multi=%d\n", a + b, a - b, a*b);
if (b == 0)
printf("The second operater is zero!");
else
printf("dev=%.2f,mod=%d\n", (float)a / b, a%b);
}
You forgot to check that x is a 4-digits number. So if the input is 12345 or 123 you don't satisfy the requirement.
#include <stdio.h>
int main()
{
int x, a, b;
int passed = 0;
// Enter a 4 digits number: ABCD
do {
printf("Enter X = ");
scanf("%d", &x);
passed = (x >= 1000 && x <= 9999) || (x >= -9999 && x <= -1000);
} while (!passed);
a = x / 100;
b = x % 100;
printf("Numbers: %d %d \n", a, b);
printf("Sum = %d \n", a + b);
printf("Sub = %d \n", a - b);
printf("Mul = %d \n", a * b);
if (0 == b) {
printf("Div by Zero \n");
} else {
printf("Div = %f \n", (double)a / b);
printf("Mod = %d \n", a % b);
}
return 0;
}
I want to Prompt the user to enter 3 numbers. Then, swap the first number with the second one, the second number with the third and the third with the first by calling a function called "swap".
Functions in C cannot return more than one value so I decided to create a structure with pointers that I will later use in my function. Then, I created three-pointers that will store the address of each one of the numbers so I can dereference to these numbers in my function (as shown below)
Number.pa = *ppb;
Number.pb = *ppc;
Number.pc = *ppa;
Here's my code:
#include <stdio.h>
void swap(); // a = b, b = c, c = a
struct Numbers {
int *pa, *pb, *pc;
} ;
int main(void) {
struct Numbers Number; // Structure to hold the values of the three variables.
int a, b, c;
int *ppa, *ppb, *ppc;
printf("\n Please enter three integer numbers: ");
scanf("%d%d%d", &a, &b, &c);
ppa = &a; ppb = &b; ppc = &c;
swap(a, b, c, Number, *ppa, *ppb, *ppc);
printf("\n %d \t %d \t %d \n", Number.pa, Number.pb, Number.pc);
}
void swap(int a, int b, int c, struct Numbers Number, int *ppa, int *ppb, int *ppc) {
Number.pa = *ppb;
Number.pb = *ppc;
Number.pc = *ppa;
} ;
Most of the arguments to your swap function are either pointless or the work of sheer guessing (or both). The assignment effectively wants you to "rotate" values from a through c. So do that, and only that.
#include <stdio.h>
void swap(int *pa, int *pb, int *pc);
int main()
{
int a, b, c;
printf("\n Please enter three integer numbers: ");
if (scanf("%d %d %d", &a, &b, &c) == 3)
{
swap(&a, &b, &c);
printf("%d %d %d \n", a, b, c);
}
return 0;
}
void swap(int *pa, int *pb, int *pc)
{
int tmp = *pa;
*pa = *pb;
*pb = *pc;
*pc = tmp;
}
Stop reading more into an assignment than is there. If it sounds simple, it probably is. The warning was due to passing the value of dereferenced pointers to int (so int values) to a function expecting int pointers; not int values. As you can see, you don't need to do any of that (and didn't in the first place).
I was trying to find the sum of 5 numbers (in C Language) using tutorials from "thenewboston" on Youtube. My code is:
int main(int argc, char *argv[]) {
int a, b, c, d, e;
int array[5]={a, b, c, d, e};
int sum=0;
int i;
int j;
printf("Enter your 5 numbers: ");
scanf("%d, %d, %d, %d, %d", &a, &b, &c, &d, &e);
for (i = 0; i < 5; i++){
sum+=array[i];
}
printf("The sum of 5 numbers is:%d",sum);
return 0;
}
But the weird thing was, no matter what 5 numbers I entered, I always got the sum as 48.
Either discard variables a, b, c, d, e and the array remains or vice versa
Remove variables on your first printf:
print("Enter 5 numbers: ");
Don't put variables when you did't use them.
When you put scanf as scanf("%d, %d", &var1, &var2);, you must also input the same format as
Enter 5 numbers: 10, 20
Working example(more efficient with array):
int main() {
int input[5];
int sum;
printf("Enter 5 numbers: ");
scanf("%d, %d, %d, %d, %d", &input[0], &input[1], &input[2], &input[3], &input[4]);
int i;
for (i = 0; i < 5; i++) {
sum += input[i];
}
printf("The sum is %d", sum);
return 0;
}
You aren't storing a, b, c, d, or e into the array array. You need to store them in the array after you read them in.
Your declaration of array doesn't create an array of pointers to your variables - it creates a single pointer to a contiguous block of five integer fields. You can't update those array fields by just using the addresses of a, etc., since your array doesn't point to them.
The most obvious, clear, and simple way to store them in the array (which I recommend) is:
array[0]=a;
array[1]=b;
array[2]=c;
array[3]=d;
array[4]=e;
Do this just before the beginning of your for loop.