stl中map函数

C ++ STL映射:: empty() (C++ STL map::empty())

It is built-in function in C++ STL and used to check whether the map container is empty or not i.e whether its size is 0 or not?

它是C ++ STL中的内置函数，用于检查地图容器是否为空，即其大小是否为0？

Syntax:

句法：

    myMap.empty()

Where, myMap is the object of class map.

其中， myMap是类映射的对象。

Parameters: None - It does not accept any parameters.

参数：无-不接受任何参数。

Return value: It returns True, if map is empty and returns False, otherwise.

返回值：如果map为空，则返回True，否则返回False。

Example:

例：

#include <iostream> 
#include <map> 
using namespace std; 
int main() {
// Example of Non Empty map
map<char, string> myMap; 
myMap['i'] = "include"; 
myMap['h'] = "help"; 
if (myMap.empty()) { 
cout << "myMap is Empty !!"; 
} 
else { 
cout << "myMap contains elements , Not Empty!!"; 
} 
cout<<endl<<endl;
// Example of Empty map
map<char, int> empMap; 
if (empMap.empty()) { 
cout << "empMap is Empty !!"; 
} 
else { 
cout << "empMap contains elements , Not Empty!!"; 
} 
return 0;     
} 

Output

输出量

myMap contains elements , Not Empty!!
empMap is Empty !!

翻译自: https://www.includehelp.com/stl/map-empty-function-with-example-in-cpp-stl.aspx

stl中map函数