Questions[c]

Many times we talk about undefined, unspecified and implementation-defined behavior in c. However, what is the difference between these concepts?

I am trying to make a C console application collect (via keyboard) special Spanish characters like accents, 'ñ', etc in a scanfor in gets.

I have managed to display these characters correctly (stored in a variable or, directly, from the printf) thanks to the locale.h. I show an example:

#include <stdio.h>
// Añade paquete de idiomas
#include <locale.h>

int main(void)
{
    // Declaración de variables
    char cadena[254];

    // Establecer el idioma a español
    setlocale(LC_ALL, "spanish");

    // Mostrar correctamente los caracteres especiales del español
    printf("¡Éxito!. Se muestran los caracteres especiales del español.");

    printf("Introduce un string con caracteres especiales: ");
    gets(cadena);

    printf("El string con caracteres especiales que has introducido es: %s", cadena);

    return 0;   
}

but I still couldn't get them to be picked up correctly with the functions mentioned above.

Does anyone know how to do it?

Thank you

Doing tests I have observed that:

• setlocale(LC_ALL, "spanish");It shows the Spanish characters correctly, but it doesn't pick them up from the keyboard.
• setlocale(LC_ALL, "es_ES");It collects the Spanish characters correctly from the keyboard, but it does not display them correctly.

I'm starting a youtube course on C.

And they show that to print the values ​​of the variables it is necessary to use this operator %.

example:

int suma, a, b;
a=2;
b=3;
suma=a+b;
printf("El valor de la suma es %i", suma);

In case of integer %i, float %fand char%c

I would like to know what other uses this operator has and what attributes it has depending on the value, because I saw that I could delimit the displayed decimals using %.1for%.2f

Since in C/C++ floating-point literals without a suffix default to type double , then assigning such a literal to a float performs an implicit conversion from double to float .

float n = 3.14;

if(n == 3.14f)
   puts("Igual");

This does not print the message instead if we add the suffix f to 3.14 in the declaration of n to prevent the conversion if printed. The question is, is there a loss of precision when the conversion is carried out?

Many times one is programming in C , and comes across the segmentation fault message , what does it mean and why does it occur?