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JavaScript JavaScript Loops, Arrays and Objects Tracking Multiple Items with Arrays Accessing Items in an Array

Michelle Harrison
Michelle Harrison
8,782 Points
Posted by Michelle Harrison
Michelle Harrison
8,782 Points

DRY Programming

I applied DRY Programming to the exercise:

var shopping = [ 'carrots', 'milk', 'eggs'];

for(var i = 0; i < shopping.length; i += 1) {
    console.log(shopping[i]);
}

I tried to do document.write instead of console.log, but every item comes out as "undefined"

var shopping = [ 'carrots', 'milk', 'eggs'];
var y = ' ' + shopping[i] + ','

for(var i = 0; i < shopping.length; i += 1) {
    document.write(y);
}

I assume this is something we'll learn in a later video, but I've found that I absorb things more when I expand on the given exercises.

Michelle Harrison
Michelle Harrison
8,782 Points
Michelle Harrison
Michelle Harrison
8,782 Points

Oooh! I got it! (Well, sort of. Doing it this way will leave a comma at the end of the array.) I just had to remember about local and global scope.

var shopping = [ 'carrots', 'milk', 'eggs'];


for(var i = 0; i < shopping.length; i += 1) {
    var y = ' ' + shopping[i] + ','
    document.write(y);
}

2 Answers

Frederick Carle
Frederick Carle
7,054 Points
Frederick Carle
Frederick Carle
7,054 Points

Hi Michelle! If you want to not have to worry about the last comma, you can use the join method on the shopping array like so. 

var shopping = [ 'carrots', 'milk', 'eggs'];

var str = shopping.join(", ");

document.write(str);

No need for a for loop in this case.

Edwin Carbajal
Edwin Carbajal
4,133 Points
Edwin Carbajal
Edwin Carbajal
4,133 Points

Hi Michelle,

Fredericks answer is correct and probably easier, but if you were trying to write out the loop, this is how it would work:

var shopping = [ 'carrots', 'milk', 'eggs' ];
var y = '';

for(var i=0; i < shopping.length; i++) {
  y += " " + shopping[i];
}
document.write(y);