Check if a variable has any value from a given set - conditional-statements

Question

How can I check if a condition passes multiple values?
Example:
if(number == 1,2,3)
I know that commas don't work.

Answer 1

if (number == 1 || number == 2 || number == 3)

Answer 2

If you are using PHP, then suppose your list of numbers is an array
$list = array(1,3,5,7,9);
then for any element, you can use
if(in_array($element, $list)){
//Element present in list
}else{
//not present.
}
Function structure:
bool in_array ( mixed $needle , array $haystack [, bool $strict = FALSE ] )
Hope that helps.

Answer 3

if ((number >= 1) && (number <= 3))

Answer 4

What language?
For example in VB.NET you use the word OR, and in C# you use ||

Answer 5

Since you specify no language I add a Python solution:
if number in [1, 2, 3]:
pass

Answer 6

In T-SQL you can use the IN operator:
select * from MyTable where ID in (1,2,3)
If you are using a collection there may be a contains operator for another way to do this.
In C# for another way that may be easier to add values:
List<int> numbers = new List<int>(){1,2,3};
if (numbers.Contains(number))

Answer 7

I'll assume a C-Style language, here's a quick primer on IF AND OR logic:
if(variable == value){
//does something if variable is equal to value
}
if(!variable == value){
//does something if variable is NOT equal to value
}
if(variable1 == value1 && variable2 == value2){
//does something if variable1 is equal to value1 AND variable2 is equal to value2
}
if(variable1 == value1 || variable2 = value2){
//does something if variable1 is equal to value1 OR variable2 is equal to value2
}
if((variable1 == value1 && variable2 = value2) || variable3 == value3){
//does something if:
// variable1 is equal to value1 AND variable2 is equal to value2
// OR variable3 equals value3 (regardless of variable1 and variable2 values)
}
if(!(variable1 == value1 && variable2 = value2) || variable3 == value3){
//does something if:
// variable1 is NOT equal to value1 AND variable2 is NOT equal to value2
// OR variable3 equals value3 (regardless of variable1 and variable2 values)
}
So you can see how you can chain these checks together to create some pretty complex logic.

Answer 8

For a list of integers:
static bool Found(List<int> arr, int val)
{
int result = default(int);
if (result == val)
result++;
result = arr.FindIndex(delegate(int myVal)
{
return (myVal == val);
});
return (result > -1);
}

Answer 9

In Java you have objects that wrap primitive variables (Integer for int, Long for long, etc). if you look to compare values between a lot of complete numbers (ints), what you can do is initiate a bunch of Integer objects, stuff them inside an iterable such as an ArrayList, iterate over them and compare.
something like:
ArrayList<Integer> integers = new ArrayList<>();
integers.add(13);
integers.add(14);
integers.add(15);
integers.add(16);
int compareTo = 17;
boolean flag = false;
for (Integer in: integers) {
if (compareTo==in) {
// do stuff
}
}
of course for a few values this may be a bit unwieldy, but if you want to compare against a lot of values, it'll work nicely.
Another option is to use java Sets, you can place a lot of different values (the collection will sort your input, which is a plus) and then invoke the .contains(Object) method to locate equality.