如何使用打字稿的字符串索引接口?-howtousestringindexedinterfaceoftypescript?

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Using the indexer limits what can be put or fetched for the object using the index syntax. E.g. foo is inferred to be of type string:

使用索引器限制使用索引语法为对象添加或获取的内容。例如，foo被推断为字符串类型:

interface IDictionary {
     [index: string]: string;
}
var params = {} as IDictionary;

params['heart'] = 'HP'; // okay
var foo = params['heart']; // foo:string

The following on the other hand is an error as it will not type check:

另一方面，下面是一个错误，因为它不会键入check:

var bar:number = params['heart']; // ERROR
params['heart'] = 234; // ERROR

Complete demo:

完整的演示:

interface IDictionary {
     [index: string]: string;
}
var params = {} as IDictionary;

params['heart'] = 'HP'; // okay
var foo = params['heart']; // foo:string


var bar:number = params['heart']; // ERROR
params['heart'] = 234; // ERROR