Q
How do you extend an object with properties from other objects in Underscore.js?

Answer & Solution

Answer: Option B
Solution:
The _.extend function copies all properties from source objects to a destination object.
Related Questions on Average

How can you invoke a function a specified number of times in Underscore.js?

A). _.times

B). _.invoke

C). _.repeat

D). _.cycle

What does _.omit({name: 'Alice', age: 25, location: 'NY'}, 'age') return?

A). {name: 'Alice', location: 'NY'}

B). {age: 25}

C). {name: 'Alice', age: 25}

D). {location: 'NY'}

What is the result of _.reduce([1, 2, 3], function(sum, num) { return sum + num; }, 0)?

A). 6

B). 5

C). 3

D). 2

What does _.identity(value) return?

A). null

B). undefined

C). The same value

D). A new value

How do you check if a value is an array in Underscore.js?

A). _.isObject

B). _.isArray

C). _.isArguments

D). _.isString

What does the _.filter function do in Underscore.js?

A). Iterates over a list of elements

B). Creates a new array with transformed values

C). Filters values in a list

D). Reduces the list to a single value

What does _.pluck([{a: 1}, {a: 2}, {a: 3}], 'a') return?

A). [1, 2, 3]

B). [1, 2]

C). [2, 3]

D). [3, 1]

How do you shuffle the elements of an array in Underscore.js?

A). _.each

B). _.shuffle

C). _.sample

D). _.random

How do you generate a random number within a range in Underscore.js?

A). _.random

B). _.range

C). _.shuffle

D). _.sample

What is the output of _.last([1, 2, 3, 4, 5], 2)?

A). [1, 2]

B). [4, 5]

C). [5]

D). [3, 4, 5]