Summary of front-end pen questions

1. js object

1. How to create an array based on a comma-separated string? Create an array for the following strings and access the third element: "cats, dogs, birds, horses"

Knowledge Point: array and String Conversion. Evaluate the knowledge of the split () method. Splits a string into a String Array (splits the string into several strings based on a specific character and returns the string as an array)

VaR animalstring = "cats, dogs, birds, horses"; var animalarray = animalstring. Split (","); alert (animalarray [2]);

If alert (animalstring [2]) is used directly, t is output.

Extended: array-> string

VaR animalarray = new array ("cats, dogs, birds, horses"); var animalstring = animalarray. Join ("-"); alert (animalstring [2]);

The output is T.