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Scope of local variables is limited to function in which they are defined but State variables can have three types of scopes.
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Public − Public state variables can be accessed internally as well as via messages. For a public state variable, an automatic getter function is generated.
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Internal − Internal state variables can be accessed only internally from the current contract or contract deriving from it without using this.
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Private − Private state variables can be accessed only internally from the current contract they are defined not in the derived contract from it.
Example
pragma solidity ^0.5.0; contract C { uint public data = 30; uint internal iData= 10; function x() public returns (uint) { data = 3; // internal access return data; } } contract Caller { C c = new C(); function f() public view returns (uint) { return c.data(); //external access } } contract D is C { function y() public returns (uint) { iData = 3; // internal access return iData; } function getResult() public view returns(uint){ uint a = 1; // local variable uint b = 2; uint result = a + b; return storedData; //access the state variable } }
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