typescript TS2339：“字符串”类型上不存在属性“包含”
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TS2339: Property 'includes' does not exist on type 'string'
提问by Michael Kolber
I have seen this error mentioned in regards to string arrays but not actual strings. I have a TypeScript file with the line
我已经看到在字符串数组中提到的这个错误，但没有看到实际的字符串。我有一个带有该行的 TypeScript 文件
if (!bus.lineInfo.PublishedLineName.includes(input)) {
This gives me an error of
这给了我一个错误
TS2339: Property 'includes' does not exist on type 'string'.
busis a variable that implements the businterface:
bus是一个实现bus接口的变量：
interface bus {
"lineInfo": {
"PublishedLineName": string,
"DestinationName": string, // The headsign of the bus
"Color": string,
"TextColor": boolean | string // false if this is "FFFFFF", otherwise it's the color
},
"warnings": boolean | busWarnings
"marker"?: google.maps.Marker,
"result"?: JQuery // The search result that appears in the sidebar
}
lineInfo.PublishedLineNameis declared as a string, and String.prototype.includes()is a function according to MDN, so why does the TypeScript compiler complain about the missing property/method?
lineInfo.PublishedLineName被声明为 a string，并且String.prototype.includes()根据 MDN 是一个函数，那么为什么 TypeScript 编译器会抱怨缺少属性/方法？
回答by hgiasac
You should add es2016 or es7 libcomplierOptions in tsconfig.json. Default TypeScript doesn't support some es6 polyfill functions
您应该在 tsconfig.json 中添加 es2016 或 es7lib编译器选项。默认 TypeScript 不支持某些 es6 polyfill 函数
{
"compilerOptions": {
...
"lib": [
"dom",
"es7"
]
}
}
Or change build target to es2016 if you no longer want to support ES5 anymore
或者如果你不想再支持 ES5，将构建目标更改为 es2016
{
"compilerOptions": {
...
"target" "es2016"
}
}
