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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 word: this Only difference is it is a pointer, so you need to use the -> operator: void setX(int x) { this->x = x; } 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(.

I have a LoginForm component. I want to check before submit, that both loginName and password is set. I tried with this code (a lot of stuff omitted): class LoginForm extends Component { constructor() { super(); this.state = { error: "", loginName: "", password: "", remember: true }; } submit(e) { e.preventDefault(); if(!this.state.loginName || !this.state.password) { //this is null this.setState({ error: "Fill in both fields" }); } else { console.log("submitting form"); } } render() { return ( <div className="col-xs-12 col-sm-6 col-md-4"> <form className="login" onSubmit={this.submit}>

I'm trying to learn React concepts, especially re: state and dynamic UIs, by coding a small sports roster-like UI. I've included the code below and the whole app + visual is at http://codepen.io/emkk/pen/dGYXJO . This app basically creates player cards from an array of player objects I've defined earlier. I would like to implement sorting of the player cards upon button click. I've created a <Sort/> component that renders the said buttons. I'd attach event listeners but don't know how to have that reflected in my <Roster/> component. I have tried many different approaches with this.state but

I had done a bit of Python long back. I am however moving over to Java now. I wanted to know if there were any differences between the Python "self" method and Java "this". I know that "self" is not a keyword while "this" is. And that is pretty much what I could figure out. Am I missing anything else? About self in Python (here is the source: Python self explanation ): The reason you need to use self . is because Python does not use the @ syntax to refer to instance attributes. Python decided to do methods in a way that makes the instance to which the method belongs be passed automatically,

When I use the this keyword for accessing a non-static variable in a class, Java doesn't give any error. But when I don't use it, Java gives an error. Why must I use this ? I know when should normally I use this , but this example is very different from normal usages. Example: class Foo { // int a = b; // gives error. why ? int a = this.b; // no error. why ? int b; int c = b; int var1 = this.var2; // very interesting int var2 = this.var1; // very interesting } Jason Variables are declared first and then assigned. That class is the same as this: class Foo { int a; int b; int c = b; int var1;