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---
id: 56533eb9ac21ba0edf2244ca
title: Using Objects for Lookups
localeTitle: Uso de objetos para búsquedas
challengeType: 1
---
## Description
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< section id = 'description' >
objetos pueden considerarse como un almacenamiento de clave / valor, como un diccionario. Si tiene datos tabulares, puede usar un objeto para " buscar" valores en lugar de una instrucción < code > switch< / code > o una cadena < code > if/else< / code > . Esto es más útil cuando sabe que sus datos de entrada están limitados a un cierto rango.
Aquí hay un ejemplo de una búsqueda de alfabeto inversa simple:
< blockquote > var alpha = {< br > 1:"Z",< br > 2:"Y",< br > 3:"X",< br > 4:"W",< br > ...< br > 24:"C",< br > 25:"B",< br > 26:"A"< br > };< br > alpha[2]; // "Y"< br > alpha[24]; // "C"< br > < br > var value = 2;< br > alpha[value]; // "Y"< / blockquote >
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< / section >
## Instructions
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< section id = 'instructions' >
Convertir la instrucción switch en un objeto llamado < code > lookup< / code > . Úselo para buscar < code > val< / code > y asignar la cadena asociada a la variable de < code > result< / code > .
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< / section >
## Tests
< section id = 'tests' >
```yml
tests:
- text: < code > phoneticLookup(" alpha" )</ code > debería ser igual a < code > " Adams" </ code >
testString: 'assert(phoneticLookup("alpha") === "Adams", "< code > phoneticLookup("alpha")< / code > should equal < code > "Adams"< / code > ");'
- text: < code > phoneticLookup(" bravo" )</ code > debería ser igual a < code > " Boston" </ code >
testString: 'assert(phoneticLookup("bravo") === "Boston", "< code > phoneticLookup("bravo")< / code > should equal < code > "Boston"< / code > ");'
- text: < code > phoneticLookup(" charlie" )</ code > debe ser igual a < code > " Chicago" </ code >
testString: 'assert(phoneticLookup("charlie") === "Chicago", "< code > phoneticLookup("charlie")< / code > should equal < code > "Chicago"< / code > ");'
- text: < code > phoneticLookup(" delta" )</ code > debe ser igual a < code > " Denver" </ code >
testString: 'assert(phoneticLookup("delta") === "Denver", "< code > phoneticLookup("delta")< / code > should equal < code > "Denver"< / code > ");'
- text: < code > phoneticLookup(" echo" )</ code > debe ser igual a < code > " Easy" </ code >
testString: 'assert(phoneticLookup("echo") === "Easy", "< code > phoneticLookup("echo")< / code > should equal < code > "Easy"< / code > ");'
- text: < code > phoneticLookup(" foxtrot" )</ code > debe ser igual a < code > " Frank" </ code >
testString: 'assert(phoneticLookup("foxtrot") === "Frank", "< code > phoneticLookup("foxtrot")< / code > should equal < code > "Frank"< / code > ");'
- text: < code > phoneticLookup("" )</ code > debe ser igual a < code > undefined</ code >
testString: 'assert(typeof phoneticLookup("") === "undefined", "< code > phoneticLookup("")< / code > should equal < code > undefined< / code > ");'
- text: No debes modificar la declaración de < code > return</ code > .
testString: 'assert(code.match(/return\sresult;/), "You should not modify the < code > return</ code > statement");'
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- text: 'No debe usar < code > case</ code > , < code > switch</ code > , o < code > if</ code > declaraciones'
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testString: 'assert(!/case|switch|if/g.test(code.replace(/([/]{2}.*)|([/][*][^/*]*[*][/])/g,"")), "You should not use < code > case< / code > , < code > switch< / code > , or < code > if< / code > statements"); '
```
< / section >
## Challenge Seed
< section id = 'challengeSeed' >
< div id = 'js-seed' >
```js
// Setup
function phoneticLookup(val) {
var result = "";
// Only change code below this line
switch(val) {
case "alpha":
result = "Adams";
break;
case "bravo":
result = "Boston";
break;
case "charlie":
result = "Chicago";
break;
case "delta":
result = "Denver";
break;
case "echo":
result = "Easy";
break;
case "foxtrot":
result = "Frank";
}
// Only change code above this line
return result;
}
// Change this value to test
phoneticLookup("charlie");
```
< / div >
< / section >
## Solution
< section id = 'solution' >
```js
function phoneticLookup(val) {
var result = "";
var lookup = {
alpha: "Adams",
bravo: "Boston",
charlie: "Chicago",
delta: "Denver",
echo: "Easy",
foxtrot: "Frank"
};
result = lookup[val];
return result;
}
```
< / section >