程式學習日記，如果我幫助了你請讓我知道

let abc="true"

result=(abc==="true") 

1.

1.javascript有時會自己自動刷新

javascript window.getselection() 會被刷掉

from:http://zh.cppreference.com/w/cpp/language/explicit
struct A
{
    A(int) { }      // 转换构造函数
    A(int, int) { } // 转换构造函数 (C++11)
    operator bool() const { return true; }
};
 
struct B
{
    explicit B(int) { }
    explicit B(int, int) { }
    explicit operator bool() const { return true; }
};
 
int main()
{
    A a1 = 1;      // OK ：复制初始化选择 A::A(int)
    A a2(2);       // OK ：直接初始化选择 A::A(int)
    A a3 {4, 5};   // OK ：直接列表初始化选择 A::A(int, int)
    A a4 = {4, 5}; // OK ：复制列表初始化选择 A::A(int, int)
    A a5 = (A)1;   // OK ：显式转型进行 static_cast
    if (a1) ;      // OK ：A::operator bool()
    bool na1 = a1; // OK ：复制初始化选择 A::operator bool()
    bool na2 = static_cast<bool>(a1); // OK ：static_cast 进行直接初始化
 
//  B b1 = 1;      // 错误：复制初始化不考虑 B::B(int)
    B b2(2);       // OK ：直接初始化选择 B::B(int)
    B b3 {4, 5};   // OK ：直接列表初始化选择 B::B(int, int)
//  B b4 = {4, 5}; // 错误：复制列表初始化不考虑 B::B(int,int)
    B b5 = (B)1;   // OK ：显式转型进行 static_cast
    if (b2) ;      // OK ：B::operator bool()
//  bool nb1 = b2; // 错误：复制初始化不考虑 B::operator bool()
    bool nb2 = static_cast<bool>(b2); // OK ：static_cast 进行直接初始化
}

https://tedsieblog.wordpress.com/category/algorithm/page/2/

You can return a structure from a function (or use the = operator) without any problems. It's a well-defined part of the language. The only problem with struct b = a is that you didn't provide a complete type. struct MyObj b = a will work just fine. You can pass structures to functions as well - a structure is exactly the same as any built-in type for purposes of parameter passing, return values, and assignment.

Here's a simple demonstration program that does all three - passes a structure as a parameter, returns a structure from a function, and uses structures in assignment statements:

指令 git config --global -credential.helper store

window的

如

1.%3s代表至少3個空間可以補足裝字 "   "  可以裝abc，如果%4s就會多一個空格變" abc"