What's the left-hand side of a method invocation called?

Question

Given the following line

cat.meow(10, x);

"meow" is the "function" or "method" being called
10 is the "first argument"
x is the "second argument"

What is cat called?

I'm dissatisfied with the answer, cat is called "the object". I want to say I've heard it called the "receiver", but I don't remember where I've heard that.

Considering both 10 and x can be objects, calling cat "the object" doesn't help me distinguish this component from the argument components.

This makes it difficult to discuss the various components that makeup a function call.

using a literal on the left-hand side would not be a variable. It'd still be nice to be able to discuss the components of that type of expression as well. `[1,2,3].forEach(foo);` — Mulan, Nov 22 '14 at 03:34
In smalltalk and objective-c it would be receiver, as those languages you pass messages, not call functions. In an OOP language cat would be an object as objects has methods, and you are calling a method. — James Black, Nov 22 '14 at 03:35
Not sure why this is getting flagged as "opinion based". Calling `c` in `a.b(c)` and "argument" is not an _opinion_. — Mulan, Nov 22 '14 at 03:36
Refusing to accept that an object is called an object is an *opinion*. — slebetman, Nov 24 '14 at 07:15

score 2 · Accepted Answer · answered Jun 07 '15 at 04:13

It is called the “subject” following the subject-verb-object sentence structure that object-oriented programming mimics:

cat.meow(10, x);
|_||___||_____|
 |   |     |
 |   |     +--> object (the arguments list is a tuple object)
 |   |
 |   +--> verb (the verb is the method name with the dot)
 |
 +--> subject (quite self explanatory)

I should clarify that I call it the “subject” because it makes sense to me. However, there's no consensus on this nomenclature. Everyone has their own opinions on what it should be called.

Thank you, this is *exactly* what I was looking for. – Mulan Jun 07 '15 at 06:30 — Mulan, Jun 07 '15 at 06:30

score 1 · Answer 2 · answered Nov 22 '14 at 03:35

1

An object is an instance of a specific class. You can use it to say cat is an instance of class [put class name here], just like 10 is an instance of Integer.

answered Nov 22 '14 at 03:35

JulienD

7,102
9
50
84

score 0 · Answer 3 · answered Nov 22 '14 at 03:35

0

Normally we call that object. According to your logic, take it in this way

meow(self,10, x) - This is the actual function where self is an object like 10 and x

Same in this case - cat.meow(10,x)

answered Nov 22 '14 at 03:35

Amal Ts

857
1
6
28

What's the left-hand side of a method invocation called?

3 Answers3