* chore(learn): audit basic algorithm scripting * chore(learn): audit basic data structures * chore(learn): audit basic javascript * chore(learn): audit debugging * chore(learn): audit es6 * chore(learn): audit functional programming * chore(learn): audit intermidate algorithms * chore(learn): audit js projects * chore(learn): audit object oriented programming * chore(learn): audit regex * fix(learn): remove stray . * fix(learn): string to code * fix(learn): missed some * fix(learn): clarify strings Based on Randy's feedback, clarifies string instances where quotes were removed in favour of back ticks. * fix: apply suggestions - thanks Randy! :) Co-authored-by: Randell Dawson <5313213+RandellDawson@users.noreply.github.com> * fix: non-suggestion comments * chore(learn): remove comments from codes Removes the comments from the description and instruction code blocks to ensure that all relevant information is translatable. * fix: Apply suggestions from code review Co-authored-by: Shaun Hamilton <51722130+ShaunSHamilton@users.noreply.github.com> * fix: revert crowdin fix * Update curriculum/challenges/english/02-javascript-algorithms-and-data-structures/basic-algorithm-scripting/mutations.md Co-authored-by: Randell Dawson <5313213+RandellDawson@users.noreply.github.com> * fix: Apply suggestions from code review Co-authored-by: Shaun Hamilton <51722130+ShaunSHamilton@users.noreply.github.com> * Update curriculum/challenges/english/02-javascript-algorithms-and-data-structures/es6/use-destructuring-assignment-to-assign-variables-from-arrays.md Co-authored-by: Shaun Hamilton <51722130+ShaunSHamilton@users.noreply.github.com> * fix: Apply suggestions from code review Co-authored-by: Oliver Eyton-Williams <ojeytonwilliams@gmail.com> Co-authored-by: Shaun Hamilton <51722130+ShaunSHamilton@users.noreply.github.com> * chore: change voice * fix: Christopher Nolan * fix: expressions would evaluate * fix: will -> would * Update curriculum/challenges/english/02-javascript-algorithms-and-data-structures/object-oriented-programming/add-methods-after-inheritance.md Co-authored-by: Randell Dawson <5313213+RandellDawson@users.noreply.github.com> * fix: to work to push * Update curriculum/challenges/english/02-javascript-algorithms-and-data-structures/basic-javascript/iterate-with-javascript-for-loops.md Co-authored-by: Shaun Hamilton <51722130+ShaunSHamilton@users.noreply.github.com> * Update curriculum/challenges/english/02-javascript-algorithms-and-data-structures/object-oriented-programming/add-methods-after-inheritance.md Co-authored-by: Randell Dawson <5313213+RandellDawson@users.noreply.github.com> Co-authored-by: Randell Dawson <5313213+RandellDawson@users.noreply.github.com> Co-authored-by: Shaun Hamilton <51722130+ShaunSHamilton@users.noreply.github.com> Co-authored-by: Oliver Eyton-Williams <ojeytonwilliams@gmail.com>
88 lines
2.6 KiB
Markdown
88 lines
2.6 KiB
Markdown
---
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id: 587d78b2367417b2b2512b10
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title: Remove Items Using splice()
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challengeType: 1
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forumTopicId: 301166
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dashedName: remove-items-using-splice
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---
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# --description--
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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.
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`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:
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```js
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let array = ['today', 'was', 'not', 'so', 'great'];
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array.splice(2, 2);
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```
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Here we remove 2 elements, beginning with the third element (at index 2). `array` would have the value `['today', 'was', 'great']`.
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`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:
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```js
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let array = ['I', 'am', 'feeling', 'really', 'happy'];
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let newArray = array.splice(3, 2);
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```
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`newArray` has the value `['really', 'happy']`.
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# --instructions--
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We've initialized an array `arr`. Use `splice()` to remove elements from `arr`, so that it only contains elements that sum to the value of `10`.
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# --hints--
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You should not change the original line of `const arr = [2, 4, 5, 1, 7, 5, 2, 1];`.
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```js
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assert(
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__helpers.removeWhiteSpace(code).match(/constarr=\[2,4,5,1,7,5,2,1\];?/)
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);
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```
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`arr` should only contain elements that sum to `10`.
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```js
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assert.strictEqual(
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arr.reduce((a, b) => a + b),
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10
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);
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```
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Your code should utilize the `splice()` method on `arr`.
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```js
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assert(__helpers.removeWhiteSpace(code).match(/arr\.splice\(/));
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```
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The splice should only remove elements from `arr` and not add any additional elements to `arr`.
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```js
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assert(
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!__helpers.removeWhiteSpace(code).match(/arr\.splice\(\d+,\d+,\d+.*\)/g)
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);
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```
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# --seed--
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## --seed-contents--
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```js
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const arr = [2, 4, 5, 1, 7, 5, 2, 1];
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// Only change code below this line
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// Only change code above this line
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console.log(arr);
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```
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# --solutions--
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```js
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const arr = [2, 4, 5, 1, 7, 5, 2, 1];
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arr.splice(1, 4);
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```
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