具有默认参数的功能

Question

我制作了一个简单的递归程序，并使用默认参数计算程序中出现7次的次数，但是程序显示错误。

const assert = require('assert');
const ganache = require('ganache-cli');
const Web3 = require('web3');
const web3 = new Web3(ganache.provider());
const { interface,bytecode} = require('../compile');

let accounts;
let inbox;

beforeEach( async() => {
accounts = await web3.eth.getAccounts();
inbox = await new web3.eth.Contract(JSON.parse(interface))
  .deploy({data: bytecode,arguments:['Hi There !'] })
  .send({from: accounts[0], gas:'1000000'});
});

describe("inbox", () => {
it('deploys a contract', () => {
    console.log(inbox);
 })
})

预期输出为2，但收到错误消息

#include <stdio.h>
int count7(int n,int c = 0)
{
    if(n==0)
        return c;
    if(n%10==7)
        c++;
    return count7(n/10,c);
}
int main()
{
    printf("Hello World");
    printf("%d",count7(727));
    return 0;
}