how to set a int value passed by parameter to a fu

问题:

how to set a int value passed by parameter to a function and assign it to global so I can use outside of the function?

Example:

int assignValues(int valor_assign1, valor_assign2){
    valor_assign1 = 7;
    valor_assign2 = 3;
}

  main (){  
int valor1 = 0;
int valor2 = 0;

assignValues(valor1,valor2);
printf("%d,%d",valor1, valor2);
}

The output is actually 0,0 I want it to be 7,3 how do I do this? I know its a simple question but I've been trying and searching but I can't find anything like that =/ Thanks in advance.

回答1:

You could pass a pointer to your integers into the function, instead of passing the values. E.g.:

int assignValues(int *valor_assign1, int *valor_assign2){
    *valor_assign1 = 7;
    *valor_assign2 = 3;
}

main (){  
    int valor1 = 0;
    int valor2 = 0;

    assignValues(&valor1, &valor2);
    printf("%d,%d",valor1, valor2);
}

You might want to read a pointer tutorial, however.

回答2:

Pass the pointers:

int assignValues(int *valor_assign1, int *valor_assign2){
    *valor_assign1 = 7;
    *valor_assign2 = 3;
}

main (){  
    int valor1 = 0;
    int valor2 = 0;

    assignValues(&valor1,&valor2);
    printf("%d,%d",valor1, valor2);
}

回答3:

You pass pointers to the variables:

void assignvalues(int *v1, int *v2) {
    *v1 = 7;
    *v2 = 3;
}

But, in your snippet, valor1 and valor2 are not global. They are local to main. If they were global, you could just assign to them

#include <stdio.h>
int valor1;               /* global    */
int valor2;               /* variables */
int assignvalues(void) {
    valor1 = 7;
    valor2 = 3;
}
int main(void) {
    printf("%d, %d\n", valor1, valor2);
}

Note: the usage of globals is frowned upon. Your usage, with local variables, is much better.