Add tip for avoiding var

[ethers]

also mentioned in solidity docs

[JohnAllen]

Can someone expand on why? Because 'var's are mutable?

[maurelian]

Good question. Its non-explicit and kind of lazy.

The only reason I can think of to use var, is to avoid having deciding what kind of type you want to use, which shifts the cognitive load to devs reading and reviewing your code. Readability is key to security.

[JohnAllen]

Honestly when I saw 'var' I thought JavaScript and lapsed into thinking about 'const' and 'let'. But solidity just looks like JS, but is very very different. So wouldn't it make sense to enforce type declarations? I think I would do that to get developers that may be alternately writing JS and Solidity to remember that they're in a very different and unforgiving environment when writing Solidity.

On Wed, Jul 19, 2017 at 2:26 PM maurelian ***@***.***> wrote: Good question. Its non-explicit and kind of lazy. The only reason I can think of to use var, is to avoid having deciding what kind of type you want to use, which shifts the cognitive load to devs reading and reviewing your code. Readability is key to security. — You are receiving this because you commented. Reply to this email directly, view it on GitHub <#57 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/ACq8AUNFb_GjrK1dKiTQVoT1TouEMLvSks5sPfYKgaJpZM4JukNH> .

-- John J. Allen

[maurelian]

Yeah. The "solidity is like js" meme is a pretty bad one, which this var feature reinforces. Fortunately it looks like it's on its way to deprecation, as the compiler gives a warning:

browser/Untitled1.sol:8:9: Warning: The type of this variable was inferred as uint8, which can hold values between 0 and 255. This is probably not desired. Use an explicit type to silence this warning.
        var n = 2;
        ^-------^```

[maurelian]

Consolidating this with #78.