I'm trying to implement optional parameters in interface, however I get an error TS2532: Object is possibly 'undefined'., is there any way to implement optional properties like in this doc

Here are my interfaces:

// Local interface
interface SecondaryIndex {
         secondaryIndexName: string;
         addLocalSecondaryIndex: boolean;
}

// Exported Interface
export interface ILambdas extends cdk.StackProps {
  ...
  secondaryIndex?: SecondaryIndex
}

Error: TS2532: Object is possibly 'undefined':

if (props.secondaryIndex.addLocalSecondaryIndex) {
    ...
}

CodePudding user response：

Javascript's optional chaining operator (?.) to the rescue!

if (props.secondaryIndex?.addLocalSecondaryIndex) {
    ...
}

With ?., if secondaryIndex is undefined your conditional expression evaluates to undefined rather than throwing an Error. Typescript will be happy.