Printing a Collection (Simple

Problem Statement

Problem Statement: Write an algorithm to print a collection of elements using the "println" method for each element.

Given: Variable 'elements' that holds a collection of objects.

Review: Solution by Index

Here is the algorithm using an iteration index for reference.

Pseudocode:

printAll(elements) {
	for (let i = 0; i < elements.length; i++) {
		let nextElem = elements[i];
		println(nextElement.toString())
	}
}

Writing Algorithm in Pseudocode

This pseudocode allows us to simply loop over the collection 'elements' and do a println for each element.

Next we will examine the pseudocode in detail

Pseudocode:

function printAll(elements) {
	for (let nextElement of elements) {
		println(nextElement.toString())
	}
}
//Try It
let collection = [10, 20, 30, 40];
printAll(collection);

for (let nextElement in elements)

for -- says to loop
let nextElement -- says to assign the next collection element to loop variable "nextElement"
in elements -- says that this is the source (collection) that is being iterated over

for (let nextElement in elements) {
	println(nextElement)
}

{} -- The braces define the loop block. The block of code within the braces executes for every loop (with a new loop var)
println(nextElement) -- calls println with the loop var "nextElement"

Notes:

A loop variable is the same as a local variable (the local context is the "loop block").
If the loop block contains only one statement, the braces "{}" are optional.

Given Data

Let us say that the provided array is a collection of student (objects) as follows:

elements = [Riya, Asha, Chin]

   [Riya, Asha, Chin]
println(elements) {        [Riya, Asha, Chin]
    for (let nextElement in elements) {
        println(nextElement)
    }
}

Loop 1

The first loop.
Loop variable "eachElement" is assigned value "Riya" (first element in collection).

            Riya
for (let nextElement in elements) {
    println(nextElement)
             Riya
}

Loop 2

The next loop.
Loop variable "eachElement" is assigned the next collection element -- "Asha".

            Asha
for (let nextElement in elements) {
    println(nextElement.toString())
             Asha
}

Loop 3

The next loop.
Loop variable "eachElement" is assigned the next collection element -- "Chin".

            Chin
for (let nextElement in elements) {
    println(nextElement.toString())
             Chin
}

LOOP ENDS

We have run out of elements in the collection (i.e., there is no "nextElement")

The loop ends.

                  [Riya, Asha, Chin]
for (let nextElement in elements) {
    println(nextElement.toString())
}