The Underscore.js is a JavaScript library that provides a lot of useful functions like the map, filter, invoke etc even without using any built-in objects. The _.rest() is used to return the rest of the elements except the zeroth indexed element. Second parameter is used to start the search from the given indexed array. It is used to return all the array elements. When the element comes then only they are displayed except the first element of the index....

The Underscore.js is a JavaScript library that provides a lot of useful functions like the map, filter, invokes, etc even without using any built-in objects. The _.unzip() function is used to combine the same type of elements of different arrays into a single array. It matches one by one each passed array elements, to the next passed array elements. It is used when more than one homogeneous arrays (one type of elements like only numbers, works, special characters, etc) to connect all the array by matching each element to its corresponding element in the next array. It can have a number of arrays as its parameters. The result will contain the same number of arrays as the number of elements the largest array has. It is opposite to the _.zip() function....

Underscore.js is a JavaScript library that provides a lot of useful functions that help in the programming in a big way like the map, filter, invoke, etc. even without using any built-in objects....

The Underscore.js is a JavaScript library that provides a lot of useful functions like the map, filter, invoke, etc even without using any built-in objects. The _isBoolean function is used to find whether the element passed is true/ false or something else. Boolean is a subset of algebra that is used to create true/false statements. If the element has a value of either true or false then the output will be true otherwise its output will be false. It is used when we have to distinguish between the elements which have true or false values and the other elements which do not have true/false as their values....

The _.exists() Method checks whether the given value is “Existy” or not, correspondingly returning a boolean value. Both null and undefined are considered non-existy values. All other values are “Existy”....

The _.property() function is used to return a function that will return the specified property of any passed-in object....

The _.dictionary() method returns a function that will attempt to look up a field that it is given....

The _.cat() method is used to concatenate zero or more arguments into one array....

The _.isFloat() method checks whether the given value is a Float value or not, and returns the corresponding boolean value....

_.findLastIndex() function:...

Underscore.js is a JavaScript library that provides a lot of useful functions that helps in the programming in a big way like the map, filter, invoke etc even without using any built-in objects....

The _.compose() function is used to return the composition of the list of functions. The list of the function returns the value of the function that follows....