Compare the values of properties in an array with those in a separate array to filter in Angular/TypeScript

Question

Compare the values of properties in an array with those in a separate array to filter in Angular/TypeScript

There are two arrays at my disposal.

//1st array
tasks.push({ ID: 1, Address: "---", Latitude: 312313, Longitude: 21312 });
tasks.push({ ID: 3, Address: "---", Latitude: 312313, Longitude: 21312 });
//2nd array
agentTasks.push({ID:2,AgentID: 2,TaskID:1});

My current challenge is to filter the tasks array to extract only those values that are not present in the agentTasks array. For instance, task ID 1 is included in agentTasks, but 3 is not. Therefore, I am interested in retrieving the value associated with ID 3 exclusively. How can this be achieved in Angular/TypeScript?

arrays angular typescript

Answer 1

Answer №1

To streamline this process, you can utilize a Set to gather all TaskIDs from the `agentTasks` array. Then, apply the .filter() method on the `tasks` array to retain only those tasks whose `ID` is not present in the set of TaskIDs:

const tasks = [
  { ID: 1, Address: "---", Latitude: 312313, Longitude: 21312 },
  { ID: 3, Address: "---", Latitude: 312313, Longitude: 21312 }
];
const agentTasks = [{ID:2,AgentID: 2,TaskID:1}];

const taskIds = new Set(agentTasks.map(({TaskID}) => TaskID));
const res = tasks.filter(({ID}) => !taskIds.has(ID));
console.log(res);

Answer 2

To streamline this process, you can utilize a Set to gather all TaskIDs from the `agentTasks` array. Then, apply the .filter() method on the `tasks` array to retain only those tasks whose `ID` is not present in the set of TaskIDs:

const tasks = [
  { ID: 1, Address: "---", Latitude: 312313, Longitude: 21312 },
  { ID: 3, Address: "---", Latitude: 312313, Longitude: 21312 }
];
const agentTasks = [{ID:2,AgentID: 2,TaskID:1}];

const taskIds = new Set(agentTasks.map(({TaskID}) => TaskID));
const res = tasks.filter(({ID}) => !taskIds.has(ID));
console.log(res);

Answer 3

Answer №2

Ultimately, the goal is to utilize the filter array function.

A more efficient approach involves creating a Map from the agentTasks array, using the TaskID as the key. This allows for filtering tasks based on the presence or absence of a corresponding key in the Map.

//Example
const tasks = [];
tasks.push({ ID: 1, Address: "---", Latitude: 312313, Longitude: 21312 });
tasks.push({ ID: 3, Address: "---", Latitude: 312313, Longitude: 21312 });

//Another example
const agentTasks = [];
agentTasks.push({ID:2,AgentID: 2,TaskID:1});

const agentTasksMap = new Map(agentTasks.map(x => [x.TaskID, x]));
const filtered = tasks.filter(task => !agentTasksMap.has(task.ID));

console.log(filtered);

Edit: Using a Set would be a better solution, as it focuses solely on the existence of a key rather than the values in my original answer using a Map.

Answer 4

Ultimately, the goal is to utilize the filter array function.

A more efficient approach involves creating a Map from the agentTasks array, using the TaskID as the key. This allows for filtering tasks based on the presence or absence of a corresponding key in the Map.

//Example
const tasks = [];
tasks.push({ ID: 1, Address: "---", Latitude: 312313, Longitude: 21312 });
tasks.push({ ID: 3, Address: "---", Latitude: 312313, Longitude: 21312 });

//Another example
const agentTasks = [];
agentTasks.push({ID:2,AgentID: 2,TaskID:1});

const agentTasksMap = new Map(agentTasks.map(x => [x.TaskID, x]));
const filtered = tasks.filter(task => !agentTasksMap.has(task.ID));

console.log(filtered);

Edit: Using a Set would be a better solution, as it focuses solely on the existence of a key rather than the values in my original answer using a Map.

Compare the values of properties in an array with those in a separate array to filter in Angular/TypeScript

Answer №1

Answer №2

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