Harmony classes
# Brendan Eich (14 years ago)
On Jun 5, 2011, at 10:59 PM, Kam Kasravi wrote:
From the harmony classes example copied below for reference. The set health(value) {...} assigns a new value to this.health. But health is a private property, so the assignment is setting a public property. Shouldn't the assignment be private(this).health = value?
Yes, thanks -- fixed.
From the harmony classes example copied below for reference. The set health(value) {...} assigns a new value to this.health. But health is a private property, so the assignment is setting a public property. Shouldn't the assignment be private(this).health = value? class Monster { // The contextual keyword "constructor" followed by an argument // list and a body defines the body of the class’s constructor // function. public and private declarations in the constructor // declare and initialize per-instance properties. Assignments // such as this.foo = bar; set public properties. constructor(name, health) { public name = name; private health = health; }
// An identifier followed by an argument list and body defines a // method. A “method” here is simply a function property on some // object. attack(target) { log('The monster attacks ' + target); }
// The contextual keyword "get" followed by an identifier and // a curly body defines a getter in the same way that "get" // defines one in an object literal. get isAlive() { return private(this).health > 0; }
// Likewise, "set" can be used to define setters. set health(value) { if (value < 0) { throw new Error('Health must be non-negative.') } this.health = value }
// An identifier optionally followed by "=" and an expression // declares a prototype property and initializes it to the value // of that expression. "public" as a member modifier is allowed. numAttacks = 0;
// The keyword "const" followed by an identifier and an // initializer declares a constant prototype property. const attackMessage = 'The monster hits you!'; }
From the harmony classes example copied below for reference. The set health(value) {...} assigns a new value to this.health. But health is a private property, so the assignment is setting a public property. Shouldn't the assignment be private(this).health = value? class Monster { // The contextual keyword "constructor" followed by an argument // list and a body defines the body of the class’s constructor // function. public and private declarations in the constructor // declare and initialize per-instance properties. Assignments // such as this.foo = bar; set public properties. constructor(name, health) { public name = name; private health = health; } // An identifier followed by an argument list and body defines a // method. A “method” here is simply a function property on some // object. attack(target) { log('The monster attacks ' + target); } // The contextual keyword "get" followed by an identifier and // a curly body defines a getter in the same way that "get" // defines one in an object literal. get isAlive() { return private(this).health > 0; } // Likewise, "set" can be used to define setters. set health(value) { if (value < 0) { throw new Error('Health must be non-negative.') } this.health = value } // An identifier optionally followed by "=" and an expression // declares a prototype property and initializes it to the value // of that expression. "public" as a member modifier is allowed. numAttacks = 0; // The keyword "const" followed by an identifier and an // initializer declares a constant prototype property. const attackMessage = 'The monster hits you!'; } -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://mail.mozilla.org/pipermail/es-discuss/attachments/20110605/23baf21f/attachment-0001.html>