Checking if the list exists and creating lists

Now that we know how to find lists, we can change our code a bit. What we are doing next is checking if a list exists, and if it doesn't, we are going to create it.

Add the following function to your web part class.

private _createSharePointList(): void { 
  const getListUrl: string = this.context.pageContext.web.absoluteUrl  
  + "/_api/web/lists/GetByTitle('My List')";  
  this.context.spHttpClient.get(getListUrl, SPHttpClient.configurations.v1) 
  .then((response: SPHttpClientResponse) => { 
      if (response.status === 200) { 
        alert("List already exists."); 
        return; // list already exists 
      } 
      if (response.status === 404) { 
        const url: string = this.context.pageContext.web.absoluteUrl + "/_api/web/lists"; 
        const listDefinition : any = { 
                "Title": "My List", 
                "Description": "My description...