Question

我有一个代表时间的数字，我需要将此数字转换为字符串。

如n = 800，表示时间= 8:00

目前我这样做：

n = 800;
string time = '' +  n/100 + ' : ' + n % 100  ;

但是time变为8 : 0，但我希望以两位数格式分钟，例如8 : 00 有人请帮助我吗？

Answer 1

var n = 800;    
var hours = Math.floor(n/100);
var minutes = ('0' + (n%100)).slice(-2);
var time = hours + ':' + minutes;

请注意小时数的四舍五入，否则你最终会得到类似“8.56：56”的内容。

Answer 2

如果你要在这里做的只是在最后两位数之前插入一个冒号，你可以做一个字符串替换：

Object<Is...>

或者将小时和分钟切片并用冒号连接：

#include <iostream>
#include <type_traits>

template <int...> class A;
template <typename...> struct Pack;
template <int...> struct P;

template <int N, int Count, typename Front, typename Output> struct GenerateHelper;

template <int N, int Count, int... Is, typename... As>
struct GenerateHelper<N, Count, P<Is...>, Pack<As...>> :
    GenerateHelper<N, Count + 1, P<Is...>, Pack<As..., A<Is..., Count>>> {};

template <int N, int... Is, typename... As>
struct GenerateHelper<N, N, P<Is...>, Pack<As...>> {
    using type = Pack<As...>;
};

template <typename...> struct Generate;

// Simple special case just to start off.  Generate has only one pack to deal with.
template <int N, int... Is>
struct Generate<P<N, Is...>> : GenerateHelper<N, 0, P<Is...>, Pack<>> {};

int main() {
    using T = Generate<P<3,0,0>>::type;
    std::cout << std::is_same<T, Pack<A<0,0,0>, A<0,0,1>, A<0,0,2>>>::value << '\n'; // true
}

Answer 3

只是一个捷径解决方案：P

Prints the values to a stream, or to sys.stdout by default.
Optional keyword arguments:
file:  a file-like object (stream); defaults to the current sys.stdout.
sep:   string inserted between values, default a space.
end:   string appended after the last value, default a newline.
flush: whether to forcibly flush the stream.

http://jsfiddle.net/6pfhyhhg/

在javascript中将数字转换为字符串

3 个答案: