C programming: How to convert a character to an integer, float in C?

Last update on December 20 2024 13:15:12 (UTC/GMT +8 hours)

Convert character to integer, float in C.

In C, you can use the atoi() function to convert a string of characters to an integer. Here's an example code snippet:

Code:

# include <stdio.h>
#include <stdlib.h>
int main() {
    char str[] = "1234";
    int x = atoi(str);
    printf("The integer value of the string is: %d\n", x);
    char str1[] = "*1234";
    x = atoi(str1);
    printf("The integer value of the string is: %d\n", x);
    return 0;
}

Output:

The integer value of the string is: 1234
The integer value of the string is: 0

In the above code, the atoi() function is used to convert the string "1234" to the integer 1234. The function takes a string as input and returns the integer equivalent of the string. If the input string ("*1234") is not a valid integer, the atoi function returns 0.

Code to convert character to float in C:

In C, you can use the atof () function to convert a string of characters to a floating-point value. Here's an example code snippet:

Code:

#include <stdio.h>
#include <stdlib.h>

int main() {
    char char_array1[] = "45.82734";
    float float_value = atof(char_array1);
    printf("The converted value is: %f\n", float_value);
    return 0.  ;
}

Output:

The converted value is: 45.827339

In the above code, atof() function is used to convert the character array "char_array1" to a floating-point value "float_value". The function atof() takes a character array as input and returns a floating-point value.

Note that atoi() , atof() functions requires the stdlib.h header file.