[英]Alter value in object
Writing Javascript, I have an object/class with the following attributes: 在编写Javascript时,我有一个具有以下属性的对象/类:
this.option1Active = null;
this.option2Active = null;
this.option3Active = null;
this.option4Active = null;
I would like to set one of those attributes to true based on the parameter genre
我想根据参数
genre
将这些属性之一设置为true
function selectGenre (genre) {
if (genre === 'option1') {
this.option1Active = true;
}
else if (genre === 'option2') {
this.option2Active = true;
}
else if (genre === 'option3') {
this.option3Active = true;
}
else if (genre === 'option4') {
this.option4Active = true;
}
}
Though writing if statements is not a sustainable solution. 尽管编写if语句不是可持续的解决方案。 I'd like to do something like this:
我想做这样的事情:
function selectGenre (genre) {
var options = {
'option1': this.option1Active,
'option2': this.option2Active,
'option3': this.option3Active,
'option4': this.option4Active
};
options[genre] = true;
}
But that only set options[index]
to true, not eg this.option1Active
. 但这仅将
options[index]
设置为true,而不是this.option1Active
。 Is there a way to change the reference a key of an object points to? 有没有一种方法可以更改对象键指向的引用?
If not, other ways of refactoring the if statements is greatly appreciated. 如果不是,则非常感谢重构if语句的其他方法。
You can use a string for the property name to set on this
. 您可以使用字符串作为属性名称在
this
设置。
var genreOptions = {
'option1': 'option1Active',
'option2': 'option2Active',
'option3': 'option3Active',
'option4': 'option4Active'
};
function selectGenre (genre) {
this[genreOptions[genre]] = true;
}
It seems you can just append "Active"
to genre
to get the property itself: 似乎您可以仅在
genre
上附加"Active"
,以获取属性本身:
function selectGenre (genre)
{
var prop = genre + 'Active';
if (typeof this[prop] != 'undefined') {
this[prop] = true;
}
}
Though, it would be easier if you could use an array as your property instead, ie this.optionActive[3]
vs. this.option3Active
. 不过,如果您可以使用数组作为属性(
this.optionActive[3]
与this.option3Active
,则会更容易。
Is this what you want ? 这是你想要的吗 ?
var obj = {};
obj.option1Active = null;
obj.option2Active = null;
obj.option3Active = null;
obj.option4Active = null;
var options = {
option1: 'option1Active',
option2: 'option2Active',
option3: 'option3Active',
option4: 'option4Active'
};
function selectGenre(genre) {
obj[options[genre]] = true;
}
console.log(obj);
selectGenre('option2');
console.log(obj);
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