Creating an angular pipe to filter an array is a useful technique for manipulating data

Question

Creating an angular pipe to filter an array is a useful technique for manipulating data

Here is the array that needs to be filtered

[
    0: {id: 1, name: "Berlin",}
    1: {id: 2, name: "Proffesor",}
    2: {id: 4, name: "Oslo",}
    3: {id: 6, name: "Denver",}
]

This is the filter array

 [6, 16, 2, 10, 24]

Below is the pipe code snippet

export class ChatPipe implements PipeTransform {

  transform(user: Users[], args: any): any { //for users i use first array and for args I use second
    if (!user || !args) {
      return user;
      
  }
  
  let filteri = user.filter(users => users.id == args);
  
  return filteri;
};

}

I'm seeking help with filtering the first array using values from another. Can anyone assist me?

arrays angular typescript pipe

Answer 1

Answer №1

Here's a revised code snippet:

// filter the user array based on matching ids
return (user || []).filter((item: any) => (args || []).includes(item.id));

Answer 2

Here's a revised code snippet:

// filter the user array based on matching ids
return (user || []).filter((item: any) => (args || []).includes(item.id));

Answer 3

Answer №2

It appears that you are looking to filter the first array based on the values of the second array by ID, although your desired output was not explicitly stated.

To begin, ensure that your users array is structured as an array:

Instead of the current format:

[
    0: {id: 1, name: "Berlin",}
    1: {id: 2, name: "Proffesor",}
    2: {id: 4, name: "Oslo",}
    3: {id: 6, name: "Denver",}
]

Reformat it like this:

[
    {id: 1, name: "Berlin"},
    {id: 2, name: "Proffesor"},
    {id: 4, name: "Oslo"},
    {id: 6, name: "Denver"},
]

Next, adjust your pipe accordingly:

@Pipe({
    name: 'filterUsersByIds',
    pure: false
})
export class FilterUsersByIdsPipe implements PipeTransform {
    transform(users: user[], filters: number[]): any {
        if (!users || !filters) {
            return users;
        }
        
        return users.filter(user => filters.some(x => user.id === x));
    }
}

PS: Remember to declare the pipe in a module before using it in your HTML code.

Answer 4

It appears that you are looking to filter the first array based on the values of the second array by ID, although your desired output was not explicitly stated.

To begin, ensure that your users array is structured as an array:

Instead of the current format:

[
    0: {id: 1, name: "Berlin",}
    1: {id: 2, name: "Proffesor",}
    2: {id: 4, name: "Oslo",}
    3: {id: 6, name: "Denver",}
]

Reformat it like this:

[
    {id: 1, name: "Berlin"},
    {id: 2, name: "Proffesor"},
    {id: 4, name: "Oslo"},
    {id: 6, name: "Denver"},
]

Next, adjust your pipe accordingly:

@Pipe({
    name: 'filterUsersByIds',
    pure: false
})
export class FilterUsersByIdsPipe implements PipeTransform {
    transform(users: user[], filters: number[]): any {
        if (!users || !filters) {
            return users;
        }
        
        return users.filter(user => filters.some(x => user.id === x));
    }
}

PS: Remember to declare the pipe in a module before using it in your HTML code.

Creating an angular pipe to filter an array is a useful technique for manipulating data

Answer №1

Answer №2

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