Write code computes the average of all the even integers in an array. with pharo smalltalk language

user_16989813 0
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Solve the assessment in Pharo Smalltalk and please loop the whole code in two ways whileTrue: and do loops.

Here is what I tried but it gives me a wrong answer.

| x y z count elem sum |

x := #(84 45 54).
sum := 0.
z := 1.
y := x size.
elem := x at: z.

[z < y] whileTrue: [ elem even ifTrue: [sum := sum + elem.]. z := z + 1.].

Transcript clear.
Transcript show: sum.
pharo smalltalk
1 Answers

Yes is wrong because "elem" is always the same.

You have to do like this:

| x y z count elem sum |
x := #(84 45 54 ).
sum := 0.
z := 1.
y := x size.
[z <= y] whileTrue: [ 
    elem := x at: z.
    elem even ifTrue: [sum := sum + elem.]. z := z + 1.
    ].
Transcript clear.
Transcript show: sum.

or more concise

| x |

x := #(84 45 54 ).
sum := 0.
x do:[:each | each even ifTrue: [sum := sum + each.].].
Transcript clear.
Transcript show: sum.

or

| x |

x := #(84 45 54 ).
sum := x inject: 0 into: [ :sum :each | each even ifTrue: [sum + each ] ifFalse: [sum + 0]]. 
Transcript clear.
Transcript show: sum.
user_119980290
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