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

What does _.identity(value) return?

A). null

B). undefined

C). The same value

D). A new value

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

A). _.times

B). _.invoke

C). _.repeat

D). _.cycle

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

A). _.isObject

B). _.isArray

C). _.isArguments

D). _.isString

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 _.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 debounce a function in Underscore.js to limit the rate at which it can fire?

A). _.throttle

B). _.debounce

C). _.delay

D). _.once

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

A). [1, 2]

B). [4, 5]

C). [5]

D). [3, 4, 5]

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

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

A). _.extend

B). _.clone

C). _.map

D). _.filter