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id	title	challengeType
587d78b2367417b2b2512b10	Remove Items Using splice()	1

Description

Ok, so we've learned how to remove elements from the beginning and end of arrays using shift() and pop(), but what if we want to remove an element from somewhere in the middle? Or remove more than one element at once? Well, that's where splice() comes in. splice() allows us to do just that: remove any number of consecutive elements from anywhere in an array. splice() can take up to 3 parameters, but for now, we'll focus on just the first 2. The first two parameters of splice() are integers which represent indexes, or positions, of the array that splice() is being called upon. And remember, arrays are zero-indexed, so to indicate the first element of an array, we would use 0. splice()'s first parameter represents the index on the array from which to begin removing elements, while the second parameter indicates the number of elements to delete. For example:

let array = ['today', 'was', 'not', 'so', 'great'];

array.splice(2, 2);
// remove 2 elements beginning with the 3rd element
// array now equals ['today', 'was', 'great']

splice() not only modifies the array it's being called on, but it also returns a new array containing the value of the removed elements:

let array = ['I', 'am', 'feeling', 'really', 'happy'];

let newArray = array.splice(3, 2);
// newArray equals ['really', 'happy']

Instructions

We've defined a function, sumOfTen, which takes an array as an argument and returns the sum of that array's elements. Modify the function, using splice(), so that it returns a value of 10.

Tests

tests:
  - text: <code>sumOfTen</code> should return 10
    testString: assert.strictEqual(sumOfTen([2, 5, 1, 5, 2, 1]), 10, '<code>sumOfTen</code> should return 10');
  - text: The <code>sumOfTen</code> function should utilize the <code>splice()</code> method
    testString: assert.notStrictEqual(sumOfTen.toString().search(/\.splice\(/), -1, 'The <code>sumOfTen</code> function should utilize the <code>splice()</code> method');

Challenge Seed

function sumOfTen(arr) {
  // change code below this line

  // change code above this line
  return arr.reduce((a, b) => a + b);
}

// do not change code below this line
console.log(sumOfTen([2, 5, 1, 5, 2, 1]));

Solution

// solution required

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