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JavaScript: Get removed elements of an given array until the passed function returns true

JavaScript fundamental (ES6 Syntax): Exercise-128 with Solution

Write a JavaScript program to get removed elements of an given array until the passed function returns true.

  • Loop through the array, using a for...of loop over Array.prototype.entries() until the returned value from the function is falsy.
  • Return the removed elements, using Array.prototype.slice().
  • The callback function, fn, accepts a single argument which is the value of the element.

Sample Solution:

JavaScript Code:

//#Source https://bit.ly/2neWfJ2 
const takeWhile = (arr, func) => {
  for (const [i, val] of arr.entries()) if (func(val)) return arr.slice(0, i);
  return arr;
};

console.log(takeWhile([1, 2, 3, 4], n => n >= 3));

Sample Output:

[1,2]

Flowchart:

flowchart: Get removed elements of an given array until the passed function returns true

Live Demo:

See the Pen javascript-basic-exercise-128-1 by w3resource (@w3resource) on CodePen.


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JavaScript: Tips of the Day

Chunks an array into n smaller arrays

Example:

const tips_chunkIntoN = (arr, n) => {
  const size = Math.ceil(arr.length / n);
  return Array.from({ length: n }, (v, i) =>
    arr.slice(i * size, i * size + size)
  );
}
console.log(tips_chunkIntoN([1, 2, 3, 4, 5, 6, 7,8], 4)); 

Output:

[[1,2],[3,4],[5,6],[7,8]]