extract numbers from a string.

str = "sensor_serials": {"H1": "3637", "H2": "3638", "H3": "2787"},

I would like to extract the number 3637, 3638, and 2787 from the above string. How should I do it? Thanks!

[Star Strider]

Something is wrong with that because it throws this error —

str = 	"sensor_serials": {"H1": "3637", "H2": "3638", "H3": "2787"}

Operator ':' is not supported for operands of type 'string'.

Answer 1

[Voss]

str = 	'"sensor_serials": {"H1": "3637", "H2": "3638", "H3": "2787"}'

str = '"sensor_serials": {"H1": "3637", "H2": "3638", "H3": "2787"}'

numbers = regexp(str,'"(\d+)"','tokens');
numbers = [numbers{:}]

numbers = 1×3 cell array
    {'3637'}    {'3638'}    {'2787'}

numbers = str2double(numbers)

numbers = 1×3

3637 3638 2787

[Jasmine Zhu]

It worked and thank you!

Answer 2

[Hiro Yoshino]

You can use pattern:

pat = digitsPattern(4); % Pattern
str = 	'"sensor_serials": {"H1": "3637", "H2": "3638", "H3": "2787"}'

str = '"sensor_serials": {"H1": "3637", "H2": "3638", "H3": "2787"}'

numbers = extract(str,pat);
string(numbers)

ans = 3×1 string array
    "3637"
    "3638"
    "2787"

[Jasmine Zhu]

Thank you for your reply. Unfortunately my matlab doesn't support digitsPattern().