Use the Excel Formula to retrieve the letter title of a column

Use the Excel Formula to retrieve the letter title of a column

If it is the first column, the value is

 

Public static string getexcelcolumnlabel (INT num ){
String temp = "";

// Make sure how many letters are there
Double I = math. Floor (math. Log (25.0*(Num)/26.0 + 1)/Math. Log (26) + 1;
If (I> 1 ){
Double sub = num-26 * (math. Pow (26, I-1)-1)/25;
For (double J = I; j> 0; j --){
Temp = temp + (char) (sub/Math. Pow (26,j-1) + 65 );
Sub = sub % math. Pow (26, J-1 );
}
} Else {
Temp = temp + (char) (Num + 65 );
}
Return temp;
}