Returning majority of array elements in QGIS expression

Question

I need to identify the majority of a string in an attribute field. For example 'A,AB,C,A' -> 'A'

Since QGIS 3.18 the function array_majority() is available.

However, I use the latest stable version 3.16 and I am wondering if something similar can be done?

Something like:

array_to_string(majority(string_to_array("sumEHZ")))

• Babel: So AB should be considered to be different from A? Like: 'A, AB, A, AB, C, AB' -> AB? Why not updating to QGIS 3.22?
• parallax: Exactly, AB is different from A or B. If it is too complicated I'll probably have to update...

Answer 1

In QGIS 3.16, you can use this expression, where text is the field containing the text you want to replace:

with_variable (
 'var',
 'array_foreach (
 array_distinct (string_to_array ("text")),
 with_variable (
 ''arr'',
 @element,
 array_length (
 array_filter (
 string_to_array("text"),
 @element=@arr
 )
 )
 )
 )',
 array_get (
 array_distinct (string_to_array("text")),
 array_find (
 eval(@var),
 array_get (
 array_sort (
 eval(@var),0
 ),0
 )
 )
 )
)

Expression edited, the repeating part from the initial expression is created as a variable var and called twice with eval(@var) to make the expression a bit shorter. See the screenshot for the (otherwise unchanged) initial expression: enter image description here