Q1: | Why is it useful to know the type of data a variable holds? |
A1: | Often the data type of a variable constrains what you can do with it. You may want to make sure that a variable contains an integer or a double before using it in a mathematical calculation, for example. |
Q2: | Should I obey any conventions when naming variables? |
A2: | Your goal should always be to make your code easy to read and understand. A variable such as $ab123245 tells you nothing about its role in your script and invites typos. Keep your variable names short and descriptive. A variable named $f is unlikely to mean much to you when you return to your code after a month or so. A variable named $filename, on the other hand, should make more sense. |
Q3: | Should I learn the operator precedence table? |
A3: | There is no reason that you shouldn't, but I would save the effort for more useful tasks. By using parentheses in your expressions, you can make your code easy to read while defining your own order of precedence. |