map<CString, Component> // Dictionary // to find keys and values // the best way

Question

Hello,

I have a dictionary and need to find a specific element. What options do I have in C++?

A) I would like to find the key, filter with key

• string, string
• string, component

B) I would like to find the keys by specifying the value

• string, string
• string, component

C) TrueOfAll() Check are all Components in the list/map are true? (IsReported)

I would like to change the Component.Unit based on the key found. Permanently, by reference Temporary, by value

Do you have any examples of how I can reach this goal? Thank you in advance.

struct Component
{
	CString Name;
	CString Value;
	CString Unit;
    bool IsReported;
};

map<CString, CString> m_DicConfigMaterials;
map<CString, Component> m_DicProcessdata;	

// The goal is 
//if key == "TestKey" then return Value;

const auto it = std::find_if(m_DicConfigMaterials.begin(), m_DicConfigMaterials.end(), [](const Component& d) { return d.Name; });

if (it == m_DicConfigMaterials.end())
{
	// not found
	// . . .
}
else
{
	// found
	var t1 = it - m_DicConfigMaterials.begin();
	// . . .
}

Answer 1

Hi, @Markus Freitag

Eg.

data

    std::map<std::string, Component> m_DicProcessdata = {
        {"TableMotorPosY", {"TableMotorPosY", "80", "mm", false}},
        {"TableMotorPosA", {"TableMotorPosA", "90", "mm", true}},
        {"TableMotorPosB", {"TableMotorPosB", "50", "mm", true}},
        {"TableMotorPosC", {"TableMotorPosC", "150", "mm", true}},
        {"EnvironmentalTemperature", {"EnvironmentalTemperature", "50", "°C", false}}
    };

ProcessKeys whose value is >80

use std::stoi

   const int value = 80;
    for (const auto& it : m_DicProcessdata) {
        if (std::stoi(it.second.Value) > value) {
            std::cout << "ProcessKey: " << it.first << ", Value: " << it.second.Value << std::endl;
        }
    }

std::map::find()

const std::string substringToFind = "TableMotorPos";

   for (const auto& it : m_DicProcessdata) {
       if (it.first.find(substringToFind) != std::string::npos) {
           std::cout << "ProcessKey: " << it.first << ", is: " << it.second.Value << std::endl;
       }
   }

The value should be able to update using operator [].

Best regards,

Minxin Yu

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