basic if statement, operator <= undefined

Question

I'm new to programming

if( (N%2==0) && (6<=N<=20) ) 

Throws the error below

The operator <= is undefined for the argument type(s) boolean , int
Please help me fix it.

Answer 1

You can't compound the statement like that. You need to && it.

For example,

if ((N % 2 == 0) && (6 <= N && N <= 20)) {...} 

The reason you get the error is the first condition of 6 <= N resolves to a boolean and you then attempt to check if a boolean is <= to an int . That does not compute.

Answer 2

您无法在一次检查中比较2个条件，您需要将其拆分为两个检查

if (N % 2 == 0 && N >= 6 && N <= 20) 

Answer 3

您应该使用逻辑运算符（在这种情况下为&&）分隔条件：

if (N % 2 == 0 && N>=6 && N <= 20)