JavaScript Task Book Level 3.5

Given a text with words. Write into an array all words that begin with the letter 'a'.

Given an array of numbers, leave in it only those numbers that are divisible by 5.

Given an array of numbers, leave in it only those numbers that contain the digit zero.

Given an array of numbers, check that it contains a number that contains the digit 3.

Given a certain number:

35142

Sort the digits of this number. In our case, we should get the following:

12345

Write a program that will generate the following string:

'-1-2-3-4-5-'

The following object is given:

let obj = {
	1: {
		1: {
			1: 111,
			2: 112,
			3: 113,
		},
		2: {
			1: 121,
			2: 122,
			3: 123,
		},
	},
	2: {
		1: {
			1: 211,
			2: 212,
			3: 213,
		},
		2: {
			1: 221,
			2: 222,
			3: 223,
		},
	},
	3: {
		1: {
			1: 311,
			2: 312,
			3: 313,
		},
		2: {
			1: 321,
			2: 322,
			3: 323,
		},
	},
}

Find the sum of the elements of this object.