Question

在实例化变量时，很容易将变量传递给新对象。例如，下面的代码非常完美。

＆＃13;

var CreatureStory, zombie;
	
function CreatureStory(species, action) {
  this.species = species;
  this.action = action;
  this.story = function() {
  console.log('The ' +this.species +' is about to ' +this.action +'.');
  }
}
	
zombie = new CreatureStory('zombie', 'walk');  //variables passed in here.
	
zombie.story();  // But how would I pass them in here?

＆＃13;

但是，如果我需要在创建对象后将它们传递给对象怎么办？例如，下面的代码不会将变量放入已创建的对象中。它们的值显示为undefined。

zombie.story('zombie', 'walk');

Answer 1

您必须将参数传递给var CreatureStory, zombie; function CreatureStory(species, action) { this.species = species; this.action = action; this.story = function(species, action) { // Like this !!!! this.species = species; this.action = action; console.log('The ' +this.species +' is about to ' +this.action +'.'); } } zombie = new CreatureStory('zombie', 'walk'); //variables passed in here. zombie.story('monster', 'sleep'); // But how would I pass them in here?方法。

＆＃13;

species

＆＃13;

此外，我更新action和{{1}}属性以反映新值

Answer 2

如果您的功能不接受任何参数，则无法为其添加参数。您可以更改功能以接受参数;或在调用story

之前更改对象属性

像：

＆＃13;

var CreatureStory, zombie;
	
function CreatureStory(species, action) {
  this.species = species;
  this.action = action;
  this.story = function() {
  console.log('The ' +this.species +' is about to ' +this.action +'.');
  }
}
	
zombie = new CreatureStory('zombie', 'walk');
zombie.action = 'run';
zombie.story();  // the zombie now will run

＆＃13;

Answer 3

创建后，您可以像这样为对象赋值： zombie.action =＆＃34;坐＆＃34;

Thien zombie.story（）将返回＆＃34;这个僵尸即将坐下来＃34;

Answer 4

将this.species和this.action更改为var species和var action

var CreatureStory, zombie;
	
function CreatureStory(species, action) {
  var species = species;
  var action = action;
  this.story = function() {
  console.log('The ' +species +' is about to ' +action +'.');
  }
}
	
zombie =  new CreatureStory('zombie', 'walk');  //variables passed in here.
	
zombie.story();  // But how would I pass them in here?

Answer 5

如果我理解正确，你可以更新你的this.story函数，如下所示：

var CreatureStory, zombie;

function CreatureStory(species, action) {
  this.species = species;
  this.action = action;
  this.story = function(species, action) {
    species = species || this.species;
    action = action || this.action;
    console.log('The ' + species +' is about to ' + action +'.');
  }
}

zombie = new CreatureStory('zombie', 'walk');  //variables passed in here.

zombie.story();

Answer 6

我认为你应该尝试理解JavaScript中的原型继承：

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Inheritance_and_the_prototype_chain

之前了解原型继承模型至关重要编写利用它的复杂代码。另外，要注意代码中原型链的长度，如果是，则将其分解必须避免可能的性能问题。此外，原生原型不应该延长，除非是为了与较新的JavaScript功能兼容。

Answer 7

componentWillReceiveProps(nextProps) {
    if(nextProps.index == this.props.ordinalNumber) {
        console.log("STARTING ANIMATION!!!");
        Animated.timing(this.animatedValue, {
            toValue: 1.5,
            duration: 1000
        }).start();
    }
}

在实例化对象后如何将变量传递给函数？

7 个答案: