title: In Typescript how do I declare a function that return string type array?
body: <p><strong>Possible duplicates:</strong></p>
  
  <p><strong>Updated Description:</strong></p>
  
  <p><a href="https://stackoverflow.com/questions/12706161/in-typescript-how-do-i-declare-an-array-of-functions-that-accept-a-string-and-re">Link1</a> : In this post user talking about return string array from a function using lamda expression.</p>
  
  <p><a href="https://stackoverflow.com/questions/12736269/how-to-declare-return-types-for-functions-in-typescript">Link2</a> : In this post user talking about (how I can declare a return type of the function) as mentioned in his post.</p>
  
  <p>Both above links are not possible duplicates against my this question. So let gets started.</p>
  
  <p>What I was expecting in my code, A function that returns string array For Ex : <code>public _citiesData: string[];</code></p>
  
  <p>I have a TypeScript class definition that starts like this:</p>
  
  <pre><code>export class AppStartupData {
  public _citiesData: string[];
  
  constructor() {
      this.citiesData();
  }
  
      citiesData():string[] {
          return this._citiesData.push('18-HAZARI','A.K','ABBOTABAD');
      }
  }
  </code></pre>
  
  <p><strong>Getting Error while building my code</strong></p>
  
  <pre><code> Type 'number' is not assignable to type 'string[]'
  </code></pre>