Solidity Data Types – Understanding Fixed and Ufixed Data Types in Solidity

solidity

Can somebody explain what are the fixed and ufixed data types in Solidity. Can you give me some examples?

I expected that these are the representations of decimal numbers, but this is not a case?

Thank you for your answers!

Best Answer

According to the docs: http://solidity.readthedocs.io/en/latest/types.html#fixed-point-numbers

Fixed point numbers are not fully supported by Solidity yet. They can be declared, but cannot be assigned to or from.

So to answer your question, they exist, but you can't use them yet.

When they become supported, you'll be able to use them to represent a number with a fixed number of decimal places.

A side note, I found this question, because I need to store a dollar value in my contract. It seems as though I will either have to store cents as a uint or just use a string... probably going with cents, so that I can easily perform operations... Not sure if that helps you.

Related Solutions

Handling Decimals in Complex Math within Solidity Contracts

You need to multiply before calculations and divide after that:

int decimals = 4;
int totalValue = 275000;
int percentage = 2;

totalValue = totalValue * 10**decimals;
for (uint i = 0; i < 30; i++) {
  int AddValue = totalValue * percentage;
  AddValue = AddValue / 100;
  totalValue += AddValue;
}
totalValue = totalValue / 10**decimals;

EDIT: fixed line 5 and the percentage calculation EDIT2: Actually you don't need to multiply the percentage and will get better results - fixed

Solidity – Fixing TypeError: Type bytes Memory Not Convertible to String Memory

The string.concat function was 'fixed' to take and return strings in solidity v0.8.12, so you should change the pragma solidity ^0.8.0 to pragma solidity ^0.8.12, for example:

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.12;

contract test {
    function hi(string memory name) pure public returns(string memory){
        string memory greetings = string.concat("Hello", name);
        return greetings;
    }
}

Best Answer

Related Solutions

Handling Decimals in Complex Math within Solidity Contracts

Solidity – Fixing TypeError: Type bytes Memory Not Convertible to String Memory

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