CPIs Lab code: Confusing amount of tokens minted

[toblich]

The following lines (program and test) actually yields 98 instead of the expected 10 million.

developer-content/content/courses/onchain-development/anchor-cpi.md

Line 557 in 3a4505e

10*10^6

developer-content/content/courses/onchain-development/anchor-cpi.md

Line 676 in 3a4505e

expect(Number(userAta.amount)).to.equal((10 * 10) ^ 6);

This is actually doing a bit-XOR between 10 * 10 = 100 and 6. In the provided test code, you can just print it and see. It actually does

100 ---> 0b1100100
6   ---> 0b0000110
----------------------
98  <--- 0b1100010  (result of XOR'ing the bits)

The math should be fixed (i.e. use the proper operators/methods) to actually yield 10 million, that is 10 tokens using 6 decimal places. As this stackoverflow answer points out, the ^ in Rust is doing a bitwise XOR and not exponentiation.

[github-actions]

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[toblich]

I've just checked and the bad math is still present in the latest docs, so this issue is still valid...

[Woody4618]

Oh true good catch, it should probably be something like
let amount: u64 = 10u64 * 10u64.pow(6);

Could you open a PR?