target ever second word in a string using map function

Apply the map() function to the variable str so that every second word in the string is converted to uppercase. in javascript.

str = "hello my name is jon and i live in. canada."

>Solution :

"hello my name is jon and i live in. canada."
    .split(" ")
    .map((word, idx) => idx % 2 === 0 ? word : word.toUpperCase())
    .join(" ")

The trick is:

1. Split by spaces.
2. Map with index, but only use toUpperCase() if idx % 2 !== 0.
3. Then join back with spaces.