PHP Taskbook Level 2.6

Given a string of letters and numbers, get an array of positions of all the digits in that string.

Given an array with some numbers, for example, like this:

Write code that will reverse the numbers in this array as follows:

Given a string with a number:

Separate the triplets of numbers with spaces, starting from the end of the number. In our case, we should get the following:

Given a string:

Change the case of the letters in this line to the opposite. In our case, it should look like this:

Given some array of numbers, for example, like this:

Merge pairs of elements together:

There is a certain line with the words:

Capitalize the first character of every other word in that line. In our case, it should look like this: