Expected identifier but got "+=" purchase[msg.sender]

Hello everyone, I am just beginning with solidity , can someone tell me what mistake i have made here.

thank you gyz

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It seems like the defined of purchase is mapping(address => uint) purchase, so I think maybe the mapping can not use += with the type uint. So maybe it should be:

purchase[msg.sender] = purchase[msg.sender] + numberoftickets;

BTW, I think in the compile version of 0.7.x, you had better use the library SafeMath.sol to avoid overflow and underflow


Hi @sanjivy_raja,

Welcome to the community :wave:

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@abcoathup thank you

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@Skyge thank you so much, will try it

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