通过函数和使用方法创建对象，而不将对象存储在变量中
通过函数和使用方法创建对象，而不将对象存储在变量中
提问于 2020-12-17 09:00:18
有没有一种方法可以让函数创建对象而不将它们存储在变量let中，如以下代码所示：
var createRiver = function(name, continent, lengthInKilometers) {
if (!(this instanceof createRiver)) {
return new createRiver(name, continent, lengthInKilometers);
}
this.name = name;
this.continent = continent;
this.lengthInKilometers = lengthInKilometers;
}
let Amazon = createRiver('Amazon', 'South America', 6575) //Without let
let Danube = createRiver('Danube', 'Europe', 2850) //Without let
createRiver.prototype.isLongerThan = function(r) {
if (this.lengthInKilometers > r.lengthInKilometers) {
return true;
} else {
return false;
}
}
Danube.isLongerThan(Amazon); //flase
Amazon.isLongerThan(Danube); //true
createRiver.prototype.logRiver = function() {
console.log("The " + this.name + " river is " + this.lengthInKilometers + " kilometers long.");
}
Amazon.logRiver(); ////The Amazon river is 6575 kilometers long.
Stack Overflow用户
发布于 2020-12-17 09:13:02
您可以根据调用构造函数的结果直接调用方法。
createRiver('Amazon', 'South America', 6575).logRiver();
console.log(createRiver('Amazon', 'South America', 6575).isLongerThan(createRiver('Danube', 'Europe', 2850)));但是当您这样做时，一旦方法完成，对象就会被丢弃，因为没有对它们的永久引用。
您可以将它们推入数组中。
var createRiver = function(name, continent, lengthInKilometers) {
if (!(this instanceof createRiver)) {
return new createRiver(name, continent, lengthInKilometers);
}
this.name = name;
this.continent = continent;
this.lengthInKilometers = lengthInKilometers;
}
let arrayRiver = [];
arrayRiver.push(createRiver('Amazon', 'South America', 6575));
arrayRiver.push(createRiver('Danube', 'Europe', 2850));
console.log(arrayRiver);
createRiver.prototype.isLongerThan = function(r) {
if (this.lengthInKilometers > r.lengthInKilometers) {
return true;
} else {
return false;
}
}
// Sort rivers by length
arrayRiver.sort((r1, r2) => r1.lengthInKilometers - r2.lengthInKilometers);
createRiver.prototype.logRiver = function() {
console.log("The " + this.name + " river is " + this.lengthInKilometers + " kilometers long.");
}
// Log all rivers
arrayRiver.forEach(r => r.logRiver());
页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/65333285
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