問題描述

有沒有辦法讀取這樣的格式化字符串，例如:48754+7812=Abcs.

Is there any way to read a formatted string like this, for example :48754+7812=Abcs.

假設我有三個字符串 X、Y 和 Z，我想要

Let's say I have three stringz X,Y and Z, and I want

X = 48754 
Y = 7812
Z = Abcs

兩個數字的大小和字符串的長度可能會有所不同，所以我不想使用 substring() 或類似的東西.

The size of the two numbers and the length of the string may vary, so I dont want to use substring() or anything like that.

是否可以給C++這樣的參數

Is it possible to give C++ a parameter like this

":#####..+####..=SSS.."

所以它直接知道發生了什么?

so it knows directly what's going on?

推薦答案

一種可能性是 boost::split()，它允許指定多個分隔符并且不需要輸入大小的先驗知識:

A possibility is boost::split(), which allows the specification of multiple delimiters and does not require prior knowledge of the size of the input:

#include <iostream>
#include <vector>
#include <string>

#include <boost/algorithm/string.hpp>
#include <boost/algorithm/string/split.hpp>

int main()
{
    std::vector<std::string> tokens;
    std::string s(":48754+7812=Abcs");
    boost::split(tokens, s, boost::is_any_of(":+="));

    // "48754" == tokens[0]
    // "7812"  == tokens[1]
    // "Abcs"  == tokens[2]

    return 0;
}

或者，使用sscanf():

#include <iostream>
#include <cstdio>

int main()
{
    const char* s = ":48754+7812=Abcs";
    int X, Y;
    char Z[100];

    if (3 == std::sscanf(s, ":%d+%d=%99s", &X, &Y, Z))
    {
        std::cout << "X=" << X << "
";
        std::cout << "Y=" << Y << "
";
        std::cout << "Z=" << Z << "
";
    }

    return 0;
}

然而，這里的限制是字符串的最大長度 (Z) 必須在解析輸入之前確定.

However, the limitiation here is that the maximum length of the string (Z) must be decided before parsing the input.

這篇關于在 C++ 中讀取格式化輸入的最簡單方法?的文章就介紹到這了，希望我們推薦的答案對大家有所幫助，也希望大家多多支持html5模板網！