curriculum/challenges/english/blocks/lab-all-true-property-validator/a10d2431ad0c6a099a4b8b52.md
In this lab you will test a specific property of each object in an array to see if it always has a truthy value or not.
For example, you could be asked to test one property of the objects in an array like the following:
[{
name: "Quincy",
role: "Founder",
isBot: false
}, {
name: "Naomi",
role: "",
isBot: false
}, {
name: "Camperbot",
role: "Bot",
isBot: true
}]
If you were asked to test the name property, in the objects of this array the property name has the values of "Quincy", "Naomi", and "Camperbot", so it is always truthy.
If you were asked to test the role property, the values are "Founder", "", and "Bot", in this case "" is a falsy value, so the values are not always truthy.
Objective: Fulfill the user stories below and get all the tests to pass to complete the lab.
User Stories:
truthCheck.truthCheck function takes two arguments: an array of objects and a string representing a property name found in those objects.true if it has, and false otherwise.truthCheck([{name: "Quincy", role: "Founder", isBot: false}, {name: "Naomi", role: "", isBot: false}, {name: "Camperbot", role: "Bot", isBot: true}], "isBot") should return false.
assert.strictEqual(truthCheck(
[
{ name: "Quincy", role: "Founder", isBot: false },
{ name: "Naomi", role: "", isBot: false },
{ name: "Camperbot", role: "Bot", isBot: true }
],
"isBot"), false);
truthCheck([{name: "Quincy", role: "Founder", isBot: false}, {name: "Naomi", role: "", isBot: false}, {name: "Camperbot", role: "Bot", isBot: true}], "name") should return true.
assert.strictEqual(truthCheck(
[
{ name: "Quincy", role: "Founder", isBot: false },
{ name: "Naomi", role: "", isBot: false },
{ name: "Camperbot", role: "Bot", isBot: true }
],
"name"), true);
truthCheck([{name: "Quincy", role: "Founder", isBot: false}, {name: "Naomi", role: "", isBot: false}, {name: "Camperbot", role: "Bot", isBot: true}], "role") should return false.
assert.strictEqual(truthCheck(
[
{ name: "Quincy", role: "Founder", isBot: false },
{ name: "Naomi", role: "", isBot: false },
{ name: "Camperbot", role: "Bot", isBot: true }
],
"role"), false);
truthCheck([{name: "Pikachu", number: 25, caught: 3}, {name: "Togepi", number: 175, caught: 1}], "number") should return true.
assert.strictEqual(truthCheck(
[
{ name: "Pikachu", number: 25, caught: 3 },
{ name: "Togepi", number: 175, caught: 1 },
],
"number"), true);
truthCheck([{name: "Pikachu", number: 25, caught: 3}, {name: "Togepi", number: 175, caught: 1}, {name: "MissingNo", number: NaN, caught: 0}], "caught") should return false.
assert.strictEqual(truthCheck(
[
{ name: "Pikachu", number: 25, caught: 3 },
{ name: "Togepi", number: 175, caught: 1 },
{ name: "MissingNo", number: NaN, caught: 0 },
],
"caught"), false);
truthCheck([{name: "Pikachu", number: 25, caught: 3}, {name: "Togepi", number: 175, caught: 1}, {name: "MissingNo", number: NaN, caught: 0}], "number") should return false.
assert.strictEqual(truthCheck(
[
{ name: "Pikachu", number: 25, caught: 3 },
{ name: "Togepi", number: 175, caught: 1 },
{ name: "MissingNo", number: NaN, caught: 0 },
],
"number"), false);
truthCheck([{name: "Quincy", username: "QuincyLarson"}, {name: "Naomi", username: "nhcarrigan"}, {name: "Camperbot"}], "username") should return false.
assert.strictEqual(truthCheck(
[
{ name: "Quincy", username: "QuincyLarson" },
{ name: "Naomi", username: "nhcarrigan" },
{ name: "Camperbot" }
],
"username"), false);
truthCheck([{name: "freeCodeCamp", users: [{name: "Quincy"}, {name: "Naomi"}]}, {name: "Code Radio", users: [{name: "Camperbot"}]}, {name: "", users: []}], "users") should return true.
assert.strictEqual(truthCheck(
[
{ name: "freeCodeCamp", users: [{ name: "Quincy" }, { name: "Naomi" }] },
{ name: "Code Radio", users: [{ name: "Camperbot" }] },
{ name: "", users: [] },
],
"users"), true);
truthCheck([{id: 1, data: {url: "https://freecodecamp.org", name: "freeCodeCamp"}}, {id: 2, data: {url: "https://coderadio.freecodecamp.org/", name: "CodeRadio"}}, {id: null, data: {}}], "data") should return true.
assert.strictEqual(truthCheck(
[
{ id: 1, data: { url: "https://freecodecamp.org", name: "freeCodeCamp" } },
{ id: 2, data: { url: "https://coderadio.freecodecamp.org/", name: "CodeRadio" } },
{ id: null, data: {} },
],
"data"), true);
truthCheck([{id: 1, data: {url: "https://freecodecamp.org", name: "freeCodeCamp"}}, {id: 2, data: {url: "https://coderadio.freecodecamp.org/", name: "CodeRadio"}}, {id: null, data: {}}], "id") should return false.
assert.strictEqual(truthCheck(
[
{ id: 1, data: { url: "https://freecodecamp.org", name: "freeCodeCamp" } },
{ id: 2, data: { url: "https://coderadio.freecodecamp.org/", name: "CodeRadio" } },
{ id: null, data: {} },
],
"id"), false);
function truthCheck(collection, pre) {
return pre;
}
truthCheck([{name: "Quincy", role: "Founder", isBot: false}, {name: "Naomi", role: "", isBot: false}, {name: "Camperbot", role: "Bot", isBot: true}], "isBot");
function truthCheck(collection, pre) {
return collection.every(function(e) { return e[pre]; });
}