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JavaScript: Converts a specified number to an array of digits

JavaScript fundamental (ES6 Syntax): Exercise-7 with Solution

Write a JavaScript program to converts a specified number to an array of digits.

Note: Convert the number to a string, using the spread operator (...) to build an array.

  • Use Math.abs() to strip the number's sign.
  • Convert the number to a string, using the spread operator (...) to build an array.
  • Use Array.prototype.map() and parseInt() to transform each value to an integer.

Sample Solution:

JavaScript Code:

const digitize = n => [...`${n}`].map(i => parseInt(i));

console.log(digitize(123));
console.log(digitize(1230));

Sample Output:

[1,2,3]
[1,2,3,0]

Pictorial Presentation:

JavaScript Fundamental: Converts a specified number to an array of digits

Flowchart:

flowchart: Converts a specified number to an array of digits

Live Demo:

See the Pen javascript-basic-exercise-1-7 by w3resource (@w3resource) on CodePen.


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Previous: Write a JavaScript program to target a given value in a nested JSON object, based on the given key.
Next: Write a JavaScript program to filter out the specified values from an specified array. Return the original array without the filtered values.

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JavaScript: Tips of the Day

How to remove a specific item from an array?

Find the index of the array element you want to remove using indexOf, and then remove that index with splice.

The splice() method changes the contents of an array by removing existing elements and/or adding new elements.

const array = [2, 5, 9];

console.log(array);

const index = array.indexOf(5);
if (index > -1) {
  array.splice(index, 1);
}

// array = [2, 9]
console.log(array);

The second parameter of splice is the number of elements to remove. Note that splice modifies the array in place and returns a new array containing the elements that have been removed.

For the reason of completeness, here are functions. The first function removes only a single occurrence (i.e. removing the first match of 5 from [2,5,9,1,5,8,5]), while the second function removes all occurrences:

function removeItemOnce(arr, value) {
  var index = arr.indexOf(value);
  if (index > -1) {
    arr.splice(index, 1);
  }
  return arr;
}

function removeItemAll(arr, value) {
  var i = 0;
  while (i < arr.length) {
    if (arr[i] === value) {
      arr.splice(i, 1);
    } else {
      ++i;
    }
  }
  return arr;
}
//Usage
console.log(removeItemOnce([2,5,9,1,5,8,5], 5))
console.log(removeItemAll([2,5,9,1,5,8,5], 5))

Ref: https://bit.ly/2N9nKRp