Creating integer field from string with characters in QGIS

Question

I am trying to create a new attribute field in a layer that converts a string with characters into an integer.

EXAMPLE: 234' -> 234 or 234'* -> 234

Any ideas on how to accomplish this?

Answer 1

If you are sure the numbers you want from the string are positive and integers only, then you can use an expression in the Field Calculator like regexp_substr( "Fieldname" , '(\\d*)' ). Or, if there are possibly negatives and/or real numbers try this: round(regexp_substr( "Fieldname" , '([.-0123456789]+)' ),0).