What does _.keys({one: 1, two: 2, three: 3}) return?

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 is the result of _.map([1, 2, 3], function(num) { return num * 3; })?

A). [1, 2, 3]

B). [3, 6, 9]

C). [2, 4, 6]

D). [3, 6, 9, 12]

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]

Which function is used to clone an object in Underscore.js?

A). _.extend

B). _.clone

C). _.map

D). _.filter

Which function is used to find unique elements in an array in Underscore.js?

A). _.first

B). _.last

C). _.uniq

D). _.filter

What does _.identity(value) return?

A). null

B). undefined

C). The same value

D). A new value

Which function can be used to delay the execution of a function in Underscore.js?

A). _.defer

B). _.delay

C). _.debounce

D). _.throttle

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'}

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

A). _.isObject

B). _.isArray

C). _.isArguments

D). _.isString