How do I implement this condition as shown in this image.

CodePudding user response：

That's just in 2..4, i.e. in the integer range from 2 to 4, including the 4.

The ≤ is just some hint text provided by the IDE, similar to how you can see argument names in function calls - it's not part of the code, it's not really there. They added it to make it clearer what the .. operator does (vs until)

This might be because