C++ equivalent to Java this

Question

In Java you can refer to the current object by doing: this.x = x. How do you do this in C++?

Assume that each of these code examples are part of a class called Shape.

Java:

public void setX(int x)
{
this.x = x;
}

C++:

public:
void setX(int x)
{
//?
}

same, only because its a pointer you use a different indirection operator: `this->` — Cechner, Aug 01 '11 at 23:21
You don't usually need `this` for most operations that access members. Explicit use of `this` is fairly situational (e.g. when calling pointers-to-member-function). — Kerrek SB, Aug 02 '11 at 01:26

score 40 · Accepted Answer · answered Aug 01 '11 at 23:22

40

Same word: this

Only difference is it is a pointer, so you need to use the -> operator:

void setX(int x)
{
    this->x = x;
}

answered Aug 01 '11 at 23:22

Benjamin Lindley

Not relevant, but I remember Stroustrup somewhere saying that making this a pointer in C++ was 'probably a mistake'. – jahhaj Aug 02 '11 at 05:59
4

That's not entirely accurate. `this` as a pointer predates references; had references been invented earlier then `this` would have been a reference. – MSalters Aug 02 '11 at 07:55

score 8 · Answer 2 · answered Aug 01 '11 at 23:24

The C++ equivalent is this, but there are a few differences.

This is a pointer to the object in question, not a reference; so, you must use pointer dereferencing operators before accessing fields or methods.

(*this).method(...)
(*this).field

or, using the more popular syntax

this->method(...)
this->field

score 3 · Answer 3 · answered Aug 01 '11 at 23:21

3

The C++ equivalent is this; that is, the keyword is the same.

answered Aug 01 '11 at 23:21

Paul Sonier

2

Do not forget the `->` thats probably what the OP is missing. – Joe Aug 01 '11 at 23:22

3 Answers3