此函数包含在“boost/algorithm/string” 库中。 Boost 字符串算法库提供了 STL 中缺少的 string-related 算法的通用实现。 trim 函数用于从字符串中删除所有前导或尾随空格。输入序列已就地修改。
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trim_left():
从字符串中删除所有前导空格。
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trim_right():
从字符串中删除所有尾随空格。
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trim():
从字符串中删除所有前导和尾随空格。
用法:
Template:
trim(Input, Loc);
参数：
Input:
输入序列
Loc:
用于‘space’ 分类的语言环境
返回：
修改后的输入序列没有前导或尾随空格。
例子：
Input:
” geeks_for_geeks ”
Output:
Applied left trim:“geeks_for_geeks ”
Applied right trim:” geeks_for_geeks”
Applied trim:“geeks_for_geeks”
Explanation:
The trim_left() function removes all the leading white spaces.
The trim_right() function removes all the trailing white spaces.
The trim() function removes all the leading and trailing white spaces.
下面是使用函数boost::trim() 从字符串中删除空格的实现：
C++
// C++ program to remove white spaces
// from string using the function
// boost::trim function
#include <boost/algorithm/string.hpp>
#include <iostream>
using namespace boost::algorithm;
using namespace std;
// Driver Code
int main()
// Given Input
string s1 = " geeks_for_geeks ";
string s2 = " geeks_for_geeks ";
string s3 = " geeks_for_geeks ";
// Apply Left Trim on string, s1
cout << "The original string is:\""
<< s1 << "\" \n";
trim_left(s1);
cout << "Applied left trim:\""
<< s1 << "\" \n\n";
// Apply Right Trim on string, s2
cout << "The original string is:\""
<< s2 << "\" \n";
trim_right(s2);
cout << "Applied right trim:\""
<< s2 << "\" \n\n";
// Apply Trim on string, s3
cout << "The original string is:\""
<< s3 << "\" \n";
trim(s3);
cout << "Applied trim:\"" << s3
<< "\" \n";
return 0;
}
输出：
The original string is:" geeks_for_geeks "
Applied left trim:"geeks_for_geeks "
The original string is:" geeks_for_geeks "
Applied right trim:" geeks_for_geeks"
The original string is:" geeks_for_geeks "
Applied trim:"geeks_for_geeks"
时间复杂度：
O(N)
辅助空间：
O(1)
