Add a note about operator precedence. #9169

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Nicolas Szalay 2016-10-26 14:03:50 +02:00
parent f4a4962b21
commit c1be0c51c6
1 changed files with 11 additions and 0 deletions

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@ -344,3 +344,14 @@ it's best to use spaces between math operators to prevent confusion or unexpecte
behavior. For example, `${var.instance-count - 1}` will subtract **1** from the
`instance-count` variable value, while `${var.instance-count-1}` will interpolate
the `instance-count-1` variable value.
-> **Note:** Operator precedence is not the usual one where *Multiply* (`*`),
*Divide* (`/`), and *Modulo* (`%`) have precedence over *Add* (`+`) and *Subtract* (`-`).
The operations are made in the order they appear. Parenthesis can be used to force ordering :
```
"${2 * 4 + 3 * 3}" # computes to 33
"${3 * 3 + 2 * 4}" # computes to 44
"${(2 * 4) + (3 * 3)}" # computes to 17
"${(3 * 3) + (2 * 4)}" # computes to 17
```