Putting value of a char array into a float variable

Question

I want to put the value of an array into a float integer.

main(){
    float a;
    char array[4]="12.1";
    a=atoi(array);
    printf("%f",a);
}

When I uses this program, it gives 12.000000 as output but I want 12.100000 as output. Thanks in advance.

What do you expect from a function whose name is _Ascii To Integer_? — machine_1, Mar 15 '19 at 16:03
Slighy off topic: Oups: `"12.1"` needs 5 chars. You forgot the NUL terminator. Better write `char array[] = "12.1";`, then the length of the array will automatically be determined by the compiler. — Jabberwocky, Mar 15 '19 at 16:05
Possible duplicate of [Convert ASCII string to int/float/long](https://stackoverflow.com/questions/25085407/convert-ascii-string-to-int-float-long) — machine_1, Mar 15 '19 at 16:07
Possible duplicate of [Converting string to float in C?](https://stackoverflow.com/questions/27986672/converting-string-to-float-in-c) — Sneftel, Mar 15 '19 at 16:08
`char array[4]="12.1";` is one too few. Use `char array[]="12.1";` — Paul Ogilvie, Mar 15 '19 at 16:11
@Sneftel I don't want to print value as float. I want to transfer that value into a float variable. — Saurabh, Mar 15 '19 at 16:16
@Saurabh Yes, that's what the person asking the linked question wanted to do as well. — Sneftel, Mar 15 '19 at 16:18
Sorry guys I am noob. So, if u can remove your downvotes that will be grateful to me. — Saurabh, Mar 15 '19 at 16:35

score 5 · Accepted Answer · edited Mar 15 '19 at 16:10

5

Use of this :

atof() — Convert Character String to Float :

#include <stdlib.h>
double atof(const char *string);

This link explains about that.

edited Mar 15 '19 at 16:10

machine_1

answered Mar 15 '19 at 16:06

Paul Ogilvie · Answer 2 · 2019-03-15T16:22:27.410

3

Summarizing the answers and comments, your program should look like:

int main(void) {
    float a;
    char array[]="12.1";
    a=atof(array);
    printf("%f\n",a);
}

edited Mar 15 '19 at 16:22

answered Mar 15 '19 at 16:16

Paul Ogilvie

Output is 858993472.000000 – Saurabh Mar 15 '19 at 16:23
Btw I am using tcc. So if there is problem with compiler then i will use gcc. – Saurabh Mar 15 '19 at 16:29
Sorry I wasn't including library file. – Saurabh Mar 15 '19 at 16:34
Yes, for completeness the answer should include `#include ` and `#include ` – Pascal Cuoq Mar 15 '19 at 16:37

score 2 · Answer 3 · answered Mar 15 '19 at 16:06

2

instead of atoi () which converts character array to integer, use atof() read here

answered Mar 15 '19 at 16:06

3 Answers3