passing variables between different contract by solidity (0.5.0+ version)

Question

I writed ERC20 contract and ICO contract for a test , but I meet a lot problem with compile problem.

My ERC20 contract have own constructor

but,I also need a ICO contract(a control)for passing variables.

this is ICO contract part , the first trying is by "constructor()public"

second trying is by "function"

but final test , I got the Error report

Got 0 expected 4! so , I think the problem is that ...

『 mTokenAddress = address(new ERC20(name, decimals, symbol, totalSupply)); 』

mTokenAddress in ICO contract is address type , i reference the solution

(How to Call contract inside another contarct in solidity version 0.5.2?)

(https://stackoverflow.com/questions/54320320/how-to-call-contract-inside-another-contarct-in-solidity-version-0-5-2?fbclid=IwAR1_2fR0-j_WRJtSgyuOPVzacJBy929eWmUh0omoTN_MZovEE2GlwIilvaE)

I don't know what else I can fix now ,hope someone give some advice

Answer 1

You don't have a compilation problem, you have a runtime problem.

The statement mTokenAddress = address(new ERC20(name, decimals, symbol, totalSupply)); is compiled successfully.

The runtime problem takes place when you execute the script 2_deploy_contracts.js.

Although you haven't posted the contents of this script, I am inclined to guess that you pass 4 arguments when deploying the second contract (whose name you haven't posted either).

Note that although the ERC20 contract's constructor takes 4 arguments, the other contract's constructor takes 0 arguments. In your script, you are most likely deploying the second contract, which deploys the first contract internally. If that is indeed the case, then you shouldn't be passing any parameters when deploying that other contract.

Please note that your question is hard to answer because of all the relevant pieces of information which you haven't bothered to post, as well as because of all those un-editable screenshots.

So please post all the relevant information and only the relevant information, and please do so using plain text (no screenshots, images, links, etc)!