Extract numeric data from string in groovy

Question

I am given a string that can include both text and numeric data:

Examples:

"100 pounds" "I think 173 lbs" "73 lbs."

I am looking for a clean way to extract only the numeric data from these strings.

Here is what I'm currently doing to strip the response:

def stripResponse(String response) {
    if(response) {
        def toRemove = ["lbs.", "lbs", "pounds.", "pounds", " "]
        def toMod = response
        for(remove in toRemove) {
            toMod = toMod?.replaceAll(remove, "")
        }
        return toMod
    }
}

Answer 1

You could use findAll then convert the results into Integers:

def extractInts( String input ) {
  input.findAll( /\d+/ )*.toInteger()
}

assert extractInts( "100 pounds is 23"  ) == [ 100, 23 ]
assert extractInts( "I think 173 lbs"   ) == [ 173 ]
assert extractInts( "73 lbs."           ) == [ 73 ]
assert extractInts( "No numbers here"   ) == []
assert extractInts( "23.5 only ints"    ) == [ 23, 5 ]
assert extractInts( "positive only -13" ) == [ 13 ]

If you need decimals and negative numbers, you might use a more complex regex:

def extractInts( String input ) {
  input.findAll( /-?\d+\.\d*|-?\d*\.\d+|-?\d+/ )*.toDouble()
}

assert extractInts( "100 pounds is 23"   ) == [ 100, 23 ]
assert extractInts( "I think 173 lbs"    ) == [ 173 ]
assert extractInts( "73 lbs."            ) == [ 73 ]
assert extractInts( "No numbers here"    ) == []
assert extractInts( "23.5 handles float" ) == [ 23.5 ]
assert extractInts( "and negatives -13"  ) == [ -13 ]