How to merge 2 rows into 1 row at the same column using awk - linux

Question

I just started using the UNIX and also no much experience in scripting. Now I am struggling a lot to merge the 2 rows at the same column. Below is original data.
There columns are split into 2 rows but ideally should be in 1 row.
But I don't know how to do it.
Original File
User Middle Last
Name Name Name
Htat Ko Lin
John Smith Bill
Trying to achieve:
UserName MiddleName LastName
Htat Ko Lin
John Smith Bill
Thanks!
Htat Ko

Answer 1

This can be done using awk and for loops
awk 'NR==1{for(i=1;i<=NF;i++)a[i]=$i;next}NR==2{for(i=1;i<=NF;i++)$i=a[i]$i}1' file
Output
UserName MiddleName LastName
Htat Ko Lin
John Smith Bill
Explanation
NR==1
If the record number is 1. i.e the first record then execute the next block
for(i=1;i<=NF;i++)
Loop from one to the number of fields(NF).Incrementing by one each time.
a[i]=$i
Using i as a key set an array element in the array a to the field i ($i).
next
Skip all further instruction and move to the next record.
NR==2
Same as before but for record 2
for(i=1;i<=NF;i++)
Exactly the same as before
$i=a[i]$i
Set field i to the stored value in the array and then itself
1
Defaults to true so prints all lines unless next has been used
Additional notes
if you want keep the columns in line the easiest was to do this is to pipe that command into column -t
awk '...' file | column -t
Reduced version
awk '{for(i=1;i<=NF;i++)(NR==2&&$i=a[i]$i)||a[i]=$i}NR>1' file