Insert in dictionary in type script-CodePudding

I need to filter a dictionary in angular. I used the following code, however, I cant insert the selected items into my final dictionary! Anyone knows how to solve it? Thanks.

filterData(data: any): any{
   for (var x = 0; x < data.length; x  ){
      if(data[x].status == "true"){
         this.filteredData.push(data[x]); // Doesn't work!
      }
   }            
   return this.filteredData;     
}

filteredData is already defined in my .ts file.

CodePudding user response：

There are a few issues with the filterData() function you have provided:

The parameter data is defined as type any, which means that it could be any type. It's a good idea to specify the type of the parameter more accurately, so that you can access its properties with confidence. For example, if data is an array of objects, you could specify its type like this:

filterData(data: { status: string }[]): any {
  // ...
}

The filteredData array is defined as a property of the component, but it is not being initialized in the constructor or anywhere else. As a result, the filteredData array is undefined when you try to push items into it. To fix this, you can initialize the filteredData array in the component's constructor or in a ngOnInit lifecycle hook:

export class MyComponent implements OnInit {
  filteredData: { status: string }[];

  constructor() {
    this.filteredData = [];
  }

  ngOnInit() {
    this.filteredData = [];
  }

  // ...
}

The if statement in the for loop is checking for the string value "true", but it's possible that the status property could have a different value, such as true (without the quotes). To fix this, you can use the strict equality operator (===) to check for a boolean value:

if (data[x].status === true) {
  // ...
}

There are a few issues with the filterData() function you have provided:

The parameter data is defined as type any, which means that it could be any type. It's a good idea to specify the type of the parameter more accurately, so that you can access its properties with confidence. For example, if data is an array of objects, you could specify its type like this:

filterData(data: { status: string }[]): any {
  // ...
}

The filteredData array is defined as a property of the component, but it is not being initialized in the constructor or anywhere else. As a result, the filteredData array is undefined when you try to push items into it. To fix this, you can initialize the filteredData array in the component's constructor or in a ngOnInit lifecycle hook:

export class MyComponent implements OnInit {
  filteredData: { status: string }[];

  constructor() {
    this.filteredData = [];
  }

  ngOnInit() {
    this.filteredData = [];
  }

  // ...
}

The if statement in the for loop is checking for the string value "true", but it's possible that the status property could have a different value, such as true (without the quotes). To fix this, you can use the strict equality operator (===) to check for a boolean value:

if (data[x].status === true) {
  // ...
}

With these changes, the filterData() function should work as expected. Here's the updated function:

filterData(data: { status: string }[]): any {
  for (let x = 0; x < data.length; x  ) {
    if (data[x].status === true) {
      this.filteredData.push(data[x]);
    }
  }            
  return this.filteredData;     
}

CodePudding user response：

you need return a "new Array" (not the modified array ), see this SO.

So generally you have a function

filterData(data: any[]): any{
  //you can use directly the filter method of an array(*)
  return data.filter(x.status=="true")
}

And use

this.filteredData=this.filterData(this.data)

See that you're creating a new array

( * ) to know about differents methods of array see, e.g. for filter