89 lines
1.8 KiB
Markdown
89 lines
1.8 KiB
Markdown
---
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id: 56bbb991ad1ed5201cd392cd
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title: Manipula arreglos con shift()
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challengeType: 1
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videoUrl: 'https://scrimba.com/c/cRbVETW'
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forumTopicId: 18238
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dashedName: manipulate-arrays-with-shift
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---
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# --description--
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`pop()` siempre elimina el último elemento de un arreglo. ¿Qué tal si quieres eliminar el primero?
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Ahí es donde entra `.shift()`. Funciona igual que `.pop()`, excepto que elimina el primer elemento en lugar del último.
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Ejemplo:
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```js
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const ourArray = ["Stimpson", "J", ["cat"]];
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const removedFromOurArray = ourArray.shift();
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```
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`removedFromOurArray` tendrá una cadena con valor `Stimpson` y `ourArray` tendrá `["J", ["cat"]]`.
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# --instructions--
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Utiliza la función `.shift()` para eliminar el primer elemento de `myArray`, y asigna el valor "desplazado" a un variable nuevo `removedFromMyArray`.
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# --hints--
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`myArray` debe ser igual a `[["dog", 3]]`.
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```js
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assert(
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(function (d) {
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if (d[0][0] == 'dog' && d[0][1] === 3 && d[1] == undefined) {
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return true;
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} else {
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return false;
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}
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})(myArray)
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);
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```
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`removedFromMyArray` debe contener `["John", 23]`.
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```js
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assert(
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(function (d) {
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if (
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d[0] == 'John' &&
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d[1] === 23 &&
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typeof removedFromMyArray === 'object'
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) {
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return true;
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} else {
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return false;
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}
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})(removedFromMyArray)
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);
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```
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# --seed--
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## --after-user-code--
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```js
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if (typeof removedFromMyArray !== 'undefined') (function(y, z){return 'myArray = ' + JSON.stringify(y) + ' & removedFromMyArray = ' + JSON.stringify(z);})(myArray, removedFromMyArray);
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```
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## --seed-contents--
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```js
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// Setup
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const myArray = [["John", 23], ["dog", 3]];
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// Only change code below this line
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```
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# --solutions--
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```js
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const myArray = [["John", 23], ["dog", 3]];
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// Only change code below this line
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const removedFromMyArray = myArray.shift();
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```
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