简述(描述 语法 说明)

头文件

函数原型

参数

返回值

举例

简述

描述

重新初始化固定大小数组的元素，并释放动态数组的存储空间。

语法

Erase array

array 参数是要清除的数组变量的名称。

说明

判断数组是固定长度数组（常规）还是动态数组是很重要的，这是因为 Erase 要根据数组的类型进行不同的操作。Erase 无需为固定大小的数组还原内存。Erase 按照下表设置固定数组的元素：

数组的类型　Erase 对固定数组元素的影响

固定数值数组　将每个元素设置为 0。

固定字符串数组　将每个元素设置为零长度字符串 ("")。

对象数组　将每个元素设置为特殊值 Nothing。Erase 释放动态数组所使用的内存。在程序再次引用该动态数组之前，必须使用 ReDim 语句来重新定义该数组变量的维数。

头文件

<string>

函数原型

iterator erase(

iterator _First,

iterator _Last

);

iterator erase(

iterator _It

);

basic_string& erase(

size_type_Pos = 0,

size_type _Count = npos

);

参数

_First

An iterator addressing the position of the first element in the range to be erased.

_Last

An iterator addressing the position one past the last element in the range to be erased.

_It

An iterator addressing the position of the element in the string to be erased.

_Pos

The index of the first character in the string to be removed.

_Count

The number of elements that will be removed if there are as many in the range of the string beginning with _Pos.

返回值

For the first two member functions, an iterator addressing the first character after the last character removed by the member function. For the third member function, a reference to the string object from which the elements have been erased.

举例

// basic_string_erase.cpp

// compile with: /EHsc

#include <string>

#include <iostream>

int main( )

{

using namespace std;

// The 1st member function using a range demarcated

// by iterators

string str1 ( "Hello world" );

basic_string <char>::iterator str1_Iter;

cout << "The original string object str1 is: "

<< str1 << "." << endl;

str1_Iter = str1.erase ( str1.begin ( ) + 3 , str1.end ( ) - 1 );

cout << "The first element after those removed is: "

<< *str1_Iter << "." << endl;

cout << "The modified string object str1 is: " << str1

<< "." << endl << endl;

// The 2nd member function erasing a char pointed to

// by an iterator

string str2 ( "Hello World" );

basic_string <char>::iterator str2_Iter;

cout << "The original string object str2 is: " << str2

<< "." << endl;

str2_Iter = str2.erase ( str2.begin ( ) + 5 );

cout << "The first element after those removed is: "

<< *str2_Iter << "." << endl;

cout << "The modified string object str2 is: " << str2

<< "." << endl << endl;

// The 3rd member function erasing a number of chars

// after a char

string str3 ( "Hello computer" ), str3m;

basic_string <char>::iterator str3_Iter;

cout << "The original string object str3 is: "

<< str3 << "." << endl;

str3m = str3.erase ( 6 , 8 );

cout << "The modified string object str3m is: "

<< str3m << "." << endl;

}

输出：

The original string object str1 is: Hello world.

The first element after those removed is: d.

The modified string object str1 is: Held.

The original string object str2 is: Hello World.

The first element after those removed is: W.

The modified string object str2 is: HelloWorld.

The original string object str3 is: Hello computer.

The modified string object str3m is: Hello .