regular expression: a line of string contains only float numbers and tab/spaces

Question

what the regular expression of a line of string containing ONLY float numbers separated with spaces or tabs. The float number can be negative, like -999.999

Answer 1

A regex for a float would look like this: -?\d+\.?\d+

A whitespace separator looks like this: \s

Put them together, allow it to repeat, make sure the end has a float (not a separator):

((-?\d+\.?\d*)\s)*(-?\d+\.?\d*))

The escaping and \d vs [0-9] might change, depending on your flavor of regex.