Here is an article on the Ethereum mapping:
Ethereum mapping: A simple example
When you work with Ethereum, you often meet with the concept of cards. Maping is a data structure that allows you to store values related to specific keys (also known as “keys” or “indicators”) in a table or other data structure. In this article, we will examine how to create and use simply mapping in a global scope.
What is mapping?
In Ethereum, mapping is basically a way to store value boards that are indexed by their position in the board. Key pairs are stored in one field (“key” field) and then the index value in another field (index field). This enables effective data search and download.
Create a simple mapping
Here is a simple example of creating mapping two elements:
`Solidity
Mymappiem contract {
Uint8 [2] Public MyMap;
}
In this example, we define a contract called “mypping”, which has a number of 2 elements (“Uint8) called" MyMap ".
Fill the mapping
To finish data mapping, you can use functions that accept the key and value as arguments. Let's create two functions:
Solidity
Mymappiem contract {
Functional set (Uint8 index, uint8 value) public {
MyMap [index] = value;
}
Get (Uint8 index) Public View Returns (Uint8) {
Mymap's return [index];
}
}
In the “SET” function, we store the value given in a specific index. In the “Get” function, we return the value related to a given index.
by mapping
Now, when we created and finished our mapping, let’s use it to store some data:
`Solidity
Mymappiem contract {
Mypping MyMap;
Constructor () public {
mymap.set (0, 1); // Set the first element on the index 0
mymap.set (1, 2); // set the second element on the index 1
}
Getmyit (Uint8 index) Public View Returns (Uint8) {
Refund of MyMap.get (index);
}
}
In this example, we create a mypping agreement and set two elements in mapping using the SET function. Then we use the “Get” function to separate the mapping element.
Example use
To test our mapping, let’s call the “Getmyit” function:
`Solidity
Pragma solidity ^0.8.0;
Mycontract contract {
Mypping MyMap;
Constructor () public {
mymap.set (1, 5); // Set the element on the index 1 to 5
}
Getmyit (Uint8 index) Public View Returns (Uint8) {
Refund of MyMap.get (index);
}
}
In this example, we call the “Getmyit” function from our own contract. Since there is no index of 0 in our mapping, the function simply returns 0.
Application
The Ethereum comparison ensures a powerful way to store and download data. In this article, we examined how to simply create mapping in global coverage with reliability. Then we completed the data mapping and used it for storing and downloading elements. This example shows the flexibility of Ethereum cards and their potential applications when developing intelligent contracts.
I hope that it will help you understand the cards better! Tell me if you have additional questions or need additional examples.
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