ARRAYINSERT
Creates an array by referencing an existing array and adding specified items.
Syntax
=ARRAYINSERT("Array",index,value, value...)
Example
In this example, cell F19 contains this array, created with the ARRAY function:
#(123,789,TRUE,FALSE,"Test","a","b","c")
ARRAYINSERT creates an array to which the values Yes and No are added as the first and second items:
=ARRAYINSERT(F19,1,"Yes","No")
This is the resulting array:
#("Yes","No",123,789,FALSE,"Test","a","b","c")