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convert float to integer

six620 (2)
I want
12.345-->12
23.468-->23

i am newbie, i can do it by nearest integer y = floor(x+0.5);
but want to learn by other way, 

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#include <stdio.h>
int main(){
float f = 12.345;
int i = (int)f;   
printf(int i);  
return 0;
}


prompt
In function ‘int main()’:
error: expected ‘)’ before ‘int’
coder777 (8443)
the most simply way to convert from float to integer (with rounding) is:

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float f = 12.345;
int i = int(f + 0.5);


floor() and ceil() are somewhat cumbersome for that purpose

line 5 should be e.g.: printf("%d\n", i);

EDIT: Disregard. Yes forgot about negatives: look at Grey Wolf post
Last edited on
closed account (z05DSL3A)
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#include <stdio.h>
#include <math.h>


int main()
{
    float aFloat   = -12.545f;
    int anInt      = (int) floor(aFloat + 0.5);
    int anotherInt = (int) (aFloat + 0.5);

    printf("Floor: %d and Cast: %d\n",anInt, anotherInt);  
    
    // You have to take care with negative numbers
    int yetAnotherInt = 0;

    if (aFloat >= 0)
        yetAnotherInt = (int) (aFloat + 0.5); 
    else 
        yetAnotherInt = (int) (aFloat - 0.5);
    //
    // Can also be done as
    // int yetAnotherInt = (aFloat >= 0) ? (int)(aFloat + 0.5) : (int)(aFloat - 0.5);

    printf("Floor: %d and Cast: %d\n",anInt, yetAnotherInt);
    
    return 0;
}
 
Floor: -13 and Cast: -12
Floor: -13 and Cast: -13
Press any key to continue . . .
Last edited on
six620 (2)
Many thanks!
It is really a good place to learn C++.
I have spent 2 days on this question.
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