Checking multiple conditions in an "if" statement

[webbydebby]

Hi, in a conditional statement, I want to check whether a value is between two other values.
It seems the only way to write it is (5<=myVar && myVar<10).
Why can’t I just write something like (5<=myVar<10)?
Also, which book or reference could I look at (besides this forum) that would tell me this information?

[OzRamos]

JavaScript interprets expressions “on-the-go” based on it’s order of operations.

Actually, in this specific case, (5<=myVar<10) is true for literally any value (even undefined or NaN). That’s because 5<=myVar gets converted to a boolean value (1 or 0), either of which is smaller than 10.

I don’t have a source, but hopefully that helps.

[webbydebby]

Hi OzRamos, thank you for explaining the “on-the-go” evaluation and that the first part gets converted to a 1 or 0. That was super clear and helpful! Now I understand why the code in that block kept running!