JavaScript: Split values into two groups with condition

JavaScript fundamental (ES6 Syntax): Exercise-45 with Solution

Split Values into Two Groups by Filter

Write a JavaScript program to split values into two groups. If an element in the filter is true, the corresponding element in the collection belongs to the first group; otherwise, it belongs to the second group.

• Use Array.prototype.reduce() and Array.prototype.push() to add elements to groups, based on filter.
• If filter has a truthy value for any element, add it to the first group, otherwise add it to the second group.

Sample Solution:

JavaScript Code:

//#Source https://bit.ly/2neWfJ2
// Define a function 'bifurcate' that takes an array 'arr' and a filter array 'filter' as input.
const bifurcate = (arr, filter) =>
  // Reduce the array 'arr' using the filter array 'filter'.
  arr.reduce((acc, val, i) =>
    // Use the filter value at index 'i' to determine the destination array for the current value.
    (acc[filter[i] ? 0 : 1].push(val), acc), [[], []]);

// Test the 'bifurcate' function with an array and a filter array, and log the result.
console.log(bifurcate(['beep', 'boop', 'foo', 'bar'], [true, true, false, true])); // Output: [['beep', 'boop', 'bar'], ['foo']]

Output:

[["beep","boop","bar"],["foo"]]

Flowchart:

Live Demo:

See the Pen javascript-basic-exercise-1-45 by w3resource (@w3resource) on CodePen.

For more Practice: Solve these Related Problems:

• Write a JavaScript program that splits an array into two groups based on a corresponding boolean filter array.
• Write a JavaScript function that divides elements into two arrays: one where a predicate is true and one where it is false.
• Write a JavaScript program that partitions an array into two groups using a provided callback to test each element.

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