Base 10 to base 2,8,16 conversion in java [duplicate]

Answer 1

use this

    if (choice == 1)

          output = Integer.toString(input, 2);

      else if (choice == 2)

          output = Integer.toString(input, 8);

    // if the user chooses choice #2, it will convert from base 10 to base of 8 
     else if (choice == 3)

          output = Integer.toString(input, 16);

  else

      System.out.println("invalid entry");

Answer 2

for a decimal x (base 10) you can use respectively for binary, octal, hex conversion

Integer.toString(x, 2),

Integer.toString(x, 8)

Integer.toString(x, 16).

then to convert it back to decimal, respectively from binary, octal, hex conversion

Integer.valueOf(binary_value, 2)

Integer.valueOf(octal_value, 8)

Integer.valueOf(hex_value, 16)

in your code, change the following:

output = Integer.toString(input, 16) //replace 16 for hex, 8 for octal, 2 for binary