converting a long to string and storing in the same variable code example

Example 1: toString convert to long

long l = 12345L;
String str = new StringBuilder().append(l).toString();

Example 2: toString convert to long

long number = 45;
System.out.println(Long.toBinaryString(number)); //101101
System.out.println(Long.toOctalString(number)); //55
System.out.println(Long.toHexString(number)); //2d
System.out.println(Long.toString(number, 5)); //140