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Object literal: setter

A setter binds an object property to a function to be called when there is an attempt to set that property.

An object literal can also contain setters

defining: a setter

by prefixing the property with set (and make it a function)
let theX = null; const obj = { x(newX) { theX = newX; } }; obj.x = 'the new X'; assert.equal(theX, 'the new X');
must have exactly one parameter
let setterCalledWith = void 0; const obj = { x() { // <<<<=== it's not a setter yet! if (arguments.length === 1) { setterCalledWith = arguments[0]; } } }; assert.equal(obj.x = 'new value', setterCalledWith);
can be a computed property (an expression enclosed in [])
const publicPropertyName = 'x'; const privatePropertyName = '_' + publicPropertyName; const obj = { [privatePropertyName]: null, // write the complete setter to make the assert below pass :) }; obj.x = 'axe'; assert.equal(obj._x, 'axe');

working with/on the setter

you can use delete to remove the property (including it`s setter)
let setterCalled = false; const obj = { set x(param) { setterCalled = true; } }; // delete the property x here, to make the test pass obj.x = true; assert.equal(setterCalled, false);


Description of all the details of a setter.
"An accessor property associates a key value with one or two accessor functions ..."
The syntax definition of how to write an (accessor) method.
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