Challenge 1 of 10
Read a key
Instructions
Write `pluck(obj, key)` returning obj[key].
Editor
IntelliSense on
// Write your code below
Module 3 of 4
javascript objects
Nested access, merge, invert keys, and map over object collections.
JavaScript Practice · 0/10 completed · scroll down for every challenge
Challenge 2 of 10 · Has truthy key
Challenge 2 of 10
Has truthy key
Instructions
Write `hasTruthy(obj, key)` true when the key exists and the value is truthy.
Editor
IntelliSense on
// Write your code below
Challenge 3 of 10 · Nested path
Challenge 3 of 10
Nested path
Instructions
Write `getCity(user)` returning `user.address.city` or `undefined`.
Editor
IntelliSense on
// Write your code below
Challenge 4 of 10 · Sum values
Challenge 4 of 10
Sum values
Instructions
Write `sumValues(obj)` summing numeric values.
Editor
IntelliSense on
// Write your code below
Challenge 5 of 10 · Remove key
Challenge 5 of 10
Remove key
Instructions
Write `omit(obj, key)` returning a shallow copy without that key.
Editor
IntelliSense on
// Write your code below
Challenge 6 of 10 · Merge objects
Challenge 6 of 10
Merge objects
Instructions
Write `merge(a, b)` where b overwrites matching keys.
Editor
IntelliSense on
// Write your code below
Challenge 7 of 10 · Multiply values
Challenge 7 of 10
Multiply values
Instructions
Write `scale(obj, x)` returning a new object with each numeric value times x.
Editor
IntelliSense on
// Write your code below
Challenge 8 of 10 · Swap keys and values
Challenge 8 of 10
Swap keys and values
Instructions
Write `invert(obj)` swapping keys and string values.
Editor
IntelliSense on
// Write your code below
Challenge 9 of 10 · Empty strings to null
Challenge 9 of 10
Empty strings to null
Instructions
Write `emptyToNull(obj)` replacing `""` values with `null`.
Editor
IntelliSense on
// Write your code below
Challenge 10 of 10 · Add field to each
Challenge 10 of 10
Add field to each
Instructions
Write `tagAll(list, key, value)` adding that property to every object (new objects).
Editor
IntelliSense on
// Write your code below
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