I have two possible strings that I need to match:
+/-90000
and
+9000 / -80000
I need to recognise the two patterns separately so wrote some regex for this. The first single number string I can match like so:
/\+\/\-{1}/g
And i wrote this for the second:
/(\+(?=[0-9]+){1}|\-(?=[0-9]+){1}|\/(?=\s){1})/g
The second would also partially match the first the first number i.e. the -90000. Is there a way that they can be improved so that they match exclusively?
You can use a single expression:
^(?:(\+\/-\s*\d+)|((\+\s*\d+)\s*\/\s*(-\s*\d+)))$
The only restriction you'll have to work with would be that in the second type of input, the positive number should come first.
You'll get the matched group in matches[1] if the input was of type 1, and in matches[2] if it was of type 2. For the type-2 input, further matches of each number gets stored in matches[3] and matches[4].
You can see the demo on regex101.
Here are two solutions with slightly different semantics.
With the first, if the string is type 1 the number will be in capture group 1 (result[1]) and if it's type 2 the numbers will be in capture groups 2 and 3 (and capture group 1 will be null). The test for type 1, then, is result[1] !== null.
var a = '+/-90000';
var b = '+9000 / -80000';
var result;
var expr1 = /\+(?:\/-(\d+)|(\d+) \/ -(\d+))/;
result = a.match(expr1);
// => [ '+/-90000', '90000', null, null ]
result = b.match(expr1);
// => [ '+9000 / -80000', null, '9000', '80000' ]
With the second, if the string is type 1 the number will be in capture group 1 (and capture group 2 will be null), and if it's type 2 the numbers will be in capture groups 2 and 3. The test for type 1 is result[1] === null.
var expr2 = /\+(\d+ )?\/ ?-(\d+)/;
result = a.match(expr2);
// => [ '+/-90000', null, '90000' ]
result = b.match(expr2);
// => [ '+9000 / -80000', '9000', '80000' ]
