vJASS (Warcraft 3), 203 189 182 177 156 bytes
Using //! import zinc "<code_path>" command to exclude //! zinc and //! endzinc.
library q{integer w,e;string r="ABCDEFGHIJKLMNOPQRSTUVWXYZ",t;function onInit(){for(0<=w<25){e=w+1;t=SubString(r,w,e);BJDebugMsg(t+SubString(r,e,e+1)+t);}}}
Readable Version:
library q{
integer Index, Increment;
string Alphabets = "ABCDEFGHIJKLMNOPQRSTUVWXYZ", Letter;
function onInit(){
/*
* Index from 0 to 24
*/
for (0 <= Index < 25){
Increment = Index + 1;
// Slice
Letter = SubString(Alphabets, Index, Increment);
// Output
BJDebugMsg(Letter + SubString(Alphabets, Increment, Increment + 1) + Letter);
}
}
}
Verification purposes only:
The in-game text screen has limited space. Using Preload(), we may able to see the full output.
//! zinc
library q{
integer Index, Increment;
string Alphabets = "ABCDEFGHIJKLMNOPQRSTUVWXYZ", Letter;
function onInit(){
// Create an empty text file (Preload file).
PreloadGenClear();
PreloadGenStart();
/*
* Index from 0 to 24
*/
for (0 <= Index < 25){
Increment = Index + 1;
// Slice
Letter = SubString(Alphabets, Index, Increment);
// Output
Preload(Letter + SubString(Alphabets, Increment, Increment + 1) + Letter);
}
// Save .txt
PreloadGenEnd("CodeGolf\\testOutput.txt");
}
}
//! endzinc
