为什么这个循环不起作用？

Question

这是一个非常简单的程序.我在顶部定义了一个函数,在循环中调用了函数print.

但我收到以下错误:

prog.cpp:5: error: variable or field ‘print’ declared void
prog.cpp:5: error: ‘a’ was not declared in this scope
prog.cpp: In function ‘int main()’:
prog.cpp:11: error: ‘print’ was not declared in this scope

这里是:

#include <iostream>    
using namespace std;

void print( a ) {
    cout << a << endl;
}

int main() {
    for ( int i = 1; i <= 50; i++) {
        if ( i % 2 == 0 ) print( i );
    }

    return 0;
}

Answer 1

您忘记a在定义时声明类型print.

Answer 2

试试这个:

void print( int a ) {