PHP allows multiple comparisons to be grouped together to determine the condition of the statement. It can be done by using the following syntax:
comparison1 and|or|xor comparison2 and|or|xor comparison3 and|or|xor.
The operators that are used with comparisons are as follows:
1. and: result in positive when both comparisons are true.
2. or: result in positive when one of the comparisons or both of the comparisons are true.
3. xor: result in positive when one of the comparisons is true but not both of the comparisons.