小编sin*_*kng的帖子

我正在通过 https://reactnavigation.org/docs/en/upgrading-from-4.x.html和https://reactnavigation.org/docs/en/compatibility.html将 React Navigation 库从 4.xx 升级到 5 。

我收到错误：

NavigationDebug Error:  Error: The 'navigation' object hasn't been initialized yet. This might happen if you don't have a navigator mounted, or if the navigator hasn't finished mounting. You can ensure that all navigators have mounted after the callback to 'useEffect' is called in your root component. See https://reactnavigation.org/docs/en/navigating-without-navigation-prop.html#handling-initialization for more details.
    at dispatch (BaseNavigationContainer.tsx:202)
    at Object.acc.<computed> [as navigate] (BaseNavigationContainer.tsx:245)
    at Object.navigate (NavigationService.ts:20)
    at SplashScreen.redirectUser (splash-screen.tsx:234)
    at SplashScreen.proxiedMethod …

在生成二进制数n位
我这样做是为了得到高达16张二进制数.

n = 6                       # for 6 digits
for i in xrange(16):
    b = bin(i)[2:]
    l = len(b)
    b = str(0) * (n - l) + b
    print b

结果是这样的

000000
000001
000010
000011
000100
000101
000110
000111
001000
001001
001010
001011
001100
001101
001110
001111

但我想要的是获得这些值而不添加一系列的0s前缀.
任何人都可以帮助我.
谢谢

这个我的程序从c ++中的函数返回数组

#include <iostream>
using namespace std;

int *pTest(){
    static int a[] = {2,3,4,6,9};
    return a;
}

int main(){
    int *x;
    x = pTest();
    while(*x != NULL){
        cout << *x++ << "  ";
    }
}

根据我的输出应该是2 3 4 6 9
我的机器输出2 3 4 6 9 1,
为什么1在输出中有额外的.
我正在使用codeblocks,gcc 4.8.1