awk switch case with constant variable - gawk

Question

I have some problems with gawk an the switch case statement. When I use switch case with an constant string every thing works fine, but wenn I use a constant variable it doesn't.
For better explanation two examples.
This example works fine:
BEGIN {
...
}
END {
split($0,a,", ")
for (k in a)
{
switch (a[k])
{
case "COLUMN 1":
POSITION = k
print k,a[k]
break
default:
print "Error"
exit
break
}
}
This example gives me a Syntax Error:
BEGIN {
COLUMN_NAME = "COLUMN 1"
}
END {
split($0,a,", ")
for (k in a)
{
switch (a[k])
{
case COLUMN_NAME : #Syntax Error in this line
POSITION = k
print k,a[k]
break
default:
print "Error"
exit
break
}
}
I don't know if awk makes COLUMN_NAME an constant, but I did not find any way to force this.
I even try to use an if/else this works fine in both cases.
Edit:
Here is an explaination what the awk script should do. I have a CSV file looked like this:
COLUMN 1, COLUMN 2, COLUMN 3, COLUMN 4
1, 2, 3, 4
5, 6, 7, 8
...
but the file can even look like this:
COLUMN 3, COLUMN 2, COLUMN 4, COLUMN 1
1, 2, 3, 4
5, 6, 7, 8
...
I know the name of the column's, but I didn't know the positon. So I parse the column names with the split function and would use an switch to find the right position.

Answer 1

Here is a way to sort it out using array in awk
awk -F, 'NR==1 {for (i=1;i<=NF;i++) {split($i,t," ");c[i]=t[2]}} NR>1 {for (j=1;j<i;j++) arr[(NR-1)FS c[j]]=$j+0} END {print arr[2 FS 1]}' file
Then END prints second row, column 1
This will for first file give 5
and 8 for second file
Some more readable:
awk -F, '
NR==1 { # get the column order
for (i=1;i<=NF;i++) { # loop trough all fields
split($i,tmp," ") # get the column number
col[i]=tmp[2]} # store the column order in col
}
NR>1 { # for all data do:
for (j=1;j<i;j++) # loop trough all element
arr[(NR-1)FS col[j]]=$j+0} # store data in array arr
END {
print arr[2 FS 1]} # print data from row 2 column 1
' file

Answer 2

You can't use a variable the way you want in a switch statement.
Any switch statement can be expressed as a sequence of if/thens, so just use that instead, e.g.:
if (a[k] == COLUMN_NAME) {POSITION = k; print k,a[k]}

Answer 3

I just hit this problem... 🥴
I had to put an if statement outside of switch to handle the variable
I don't know if this happens in C as well... 🤔
🤪🔥💥💀