14. Converting int to String

As usual, in Java, we can accomplish a task in multiple ways. For instance, we can convert an int (primitive integer) to String via Integer.toString(), as follows:

public String intToStringV1(int v) {
  return Integer.toString(v);
}

Alternatively, you can accomplish this task via a quite common hack (the code reviewer will raise his eyebrow here), consisting of concatenating an empty string with the integer:

public String intToStringV2(int v) {
  return "" + v;
}

String.valueOf() can also be used as follows:

public String intToStringV3(int v) {
  return String.valueOf(v);
}

A more esoteric approach via String.format() is as follows:

public String intToStringV4(int v) {
  return String.format("%d", v);
}

These methods also work for a boxed integer and, therefore, for an Integer object. Since boxing and unboxing are costly operations, we strive to avoid them unless they are really necessary. However...