c语言中局部变量是什么

#include <stdio.h>

int f1(int a){

    int b,c;  //a,b,c仅在函数f1()内有效

    return a+b+c;

}

int main(){

    int m = 5;

    int n = 6;  //m,n仅在函数main()内有效

    printf(" m = %d n = %d \n",m,n);

    printf(" b = %d c = %d \n",b,c); //b,c 在函数中并未声明

    return 0;

}

/*

输出：

main.cpp: In function ‘int main()’:

main.cpp:11:29: error: ‘b’ was not declared in this scope

   11 |  printf(" b = %d c = %d \n",b,c);

      |                             ^

main.cpp:11:31: error: ‘c’ was not declared in this scope

   11 |  printf(" b = %d c = %d \n",b,c);

      |                               ^

*/