How to do that

Question

I want to compare something like char or string with another for example
the operators can I abbreviate this expression
if (op=='+'||op=='-'||op=='*'||op=='/'){do something}
to be like
if(op=x){do something}

Answer 1

the point is that I want to abbreviate like
char a= 'a'||'b'||'c';
if(op==a);

Answer 2

maybe its better to use the switch?

if(po=='+'){
do ...
} else if (po=='-'){
do ...
} else if (po='*'){
do ...
} else if (po=='/'){
do ...
}

Answer 3

Do you mean that if one condition is true, do something?
if (op = 'a' || op = 'b' || op = 'c') {
do...
}

Answer 4

switch
https://docs.oracle.com/javase/tutorial/java/nutsandbolts/switch.html