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---
id: a10d2431ad0c6a099a4b8b52
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title: Verificar se tudo é verdadeiro
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challengeType: 5
forumTopicId: 16011
dashedName: everything-be-true
---
# --description--
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Verifique se o predicado (segundo argumento) é < dfn > truthy< / dfn > em todos os elementos de uma coleção (primeiro argumento).
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Em outras palavras, você recebe uma coleção de array de objetos. O predicado `pre` será uma propriedade de objeto e você precisa retornar `true` se seu valor for `truthy` . Caso contrário, retorne `false` .
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Em JavaScript, valores `truthy` são valores que traduzem para `true` quando avaliados em um contexto booleano.
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Lembre-se, você pode acessar propriedades de objeto através de notação de ponto ou notação `[]` .
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# --hints--
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`truthCheck([{"user": "Tinky-Winky", "sex": "male"}, {"user": "Dipsy", "sex": "male"}, {"user": "Laa-Laa", "sex": "female"}, {"user": "Po", "sex": "female"}], "sex")` deve retornar `true` .
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```js
assert.strictEqual(
truthCheck(
[
{ user: 'Tinky-Winky', sex: 'male' },
{ user: 'Dipsy', sex: 'male' },
{ user: 'Laa-Laa', sex: 'female' },
{ user: 'Po', sex: 'female' }
],
'sex'
),
true
);
```
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`truthCheck([{"user": "Tinky-Winky", "sex": "male"}, {"user": "Dipsy"}, {"user": "Laa-Laa", "sex": "female"}, {"user": "Po", "sex": "female"}], "sex")` deve retornar `false` .
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```js
assert.strictEqual(
truthCheck(
[
{ user: 'Tinky-Winky', sex: 'male' },
{ user: 'Dipsy' },
{ user: 'Laa-Laa', sex: 'female' },
{ user: 'Po', sex: 'female' }
],
'sex'
),
false
);
```
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`truthCheck([{"user": "Tinky-Winky", "sex": "male", "age": 0}, {"user": "Dipsy", "sex": "male", "age": 3}, {"user": "Laa-Laa", "sex": "female", "age": 5}, {"user": "Po", "sex": "female", "age": 4}], "age")` deve retornar `false` .
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```js
assert.strictEqual(
truthCheck(
[
{ user: 'Tinky-Winky', sex: 'male', age: 2 },
{ user: 'Dipsy', sex: 'male', age: 0 },
{ user: 'Laa-Laa', sex: 'female', age: 5 },
{ user: 'Po', sex: 'female', age: 4 }
],
'age'
),
false
);
```
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`truthCheck([{"name": "Pete", "onBoat": true}, {"name": "Repeat", "onBoat": true}, {"name": "FastForward", "onBoat": null}], "onBoat")` deve retornar `false` .
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```js
assert.strictEqual(
truthCheck(
[
{ name: 'Pete', onBoat: true },
{ name: 'Repeat', onBoat: true },
{ name: 'FastForward', onBoat: null }
],
'onBoat'
),
false
);
```
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`truthCheck([{"name": "Pete", "onBoat": true}, {"name": "Repeat", "onBoat": true, "alias": "Repete"}, {"name": "FastForward", "onBoat": true}], "onBoat")` deve retornar `true` .
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```js
assert.strictEqual(
truthCheck(
[
{ name: 'Pete', onBoat: true },
{ name: 'Repeat', onBoat: true, alias: 'Repete' },
{ name: 'FastForward', onBoat: true }
],
'onBoat'
),
true
);
```
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`truthCheck([{"single": "yes"}], "single")` deve retornar `true` .
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```js
assert.strictEqual(truthCheck([{ single: 'yes' }], 'single'), true);
```
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`truthCheck([{"single": ""}, {"single": "double"}], "single")` deve retornar `false` .
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```js
assert.strictEqual(
truthCheck([{ single: '' }, { single: 'double' }], 'single'),
false
);
```
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`truthCheck([{"single": "double"}, {"single": undefined}], "single")` deve retornar `false` .
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```js
assert.strictEqual(
truthCheck([{ single: 'double' }, { single: undefined }], 'single'),
false
);
```
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`truthCheck([{"single": "double"}, {"single": NaN}], "single")` deve retornar `false` .
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```js
assert.strictEqual(
truthCheck([{ single: 'double' }, { single: NaN }], 'single'),
false
);
```
# --seed--
## --seed-contents--
```js
function truthCheck(collection, pre) {
return pre;
}
truthCheck([{"user": "Tinky-Winky", "sex": "male"}, {"user": "Dipsy", "sex": "male"}, {"user": "Laa-Laa", "sex": "female"}, {"user": "Po", "sex": "female"}], "sex");
```
# --solutions--
```js
function truthCheck(collection, pre) {
return collection.every(function(e) { return e[pre]; });
}
```