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How does Solidity ".call" work?
I want to invoke a method on a contract from another contract using
If the method has no parameters, it works fine, otherwise it doesnt.
For instance, this:
invokes the method
But in case the method has one parameter, what should I write?
(from here)
call.If the method has no parameters, it works fine, otherwise it doesnt.
For instance, this:
secondContract.call.value(3).gas(20764)( bytes4(sha3("ping()"))); invokes the method
ping on SecondContract , sending also 3wei and limiting gas usage to 20764.But in case the method has one parameter, what should I write?
(from here)
Comments
function setCounter(uint n){ counter = n; }then, its calling (to set the counter to 4) would be:
sec.call.gas(20764)( bytes4(sha3("setCounter(uint256)")), 4);(!!!! Please notice that the signature of the function says uint256. I was trying uint (as the declared function says) but in that way it does not work.)
I found the solution reading this, where basically they says that they hash the signature of the function and they use the first 4bytes to get the index.