Array element = 'null' displays differently in ESTK Javascript console

[FitzFoto]

Why do these two methods of presenting the contents of an array, where one or more elements is set to 'null', give a different display?

var x

x = [ 1, null, null ];

$.writeln( x );

$.writeln( x[0] + "," + x[1] + "," + x[2] );

The results displayed are:

     1,,

and:

     1,null,null

respectively.

It's consistent regardless of whether x is declared as above, or as: 'new Array', or as: 'new Array( 3 )'.

Just wondering.  It had me chasing my tail for a while during debugging.

[Kukurykus]

Not an answer, but when in the additional line you type: x[1], so directly cell of an array, you'll have null displayed. Probably the same happens when you put specified cell to writeln. For a reason in array they still exist as they are, so as true values in the contrary to calling a single input. Then they are shown as result so in the understable converted form. You do not need that but you can try to make string from array by x.toSource()

[FitzFoto]

Indeed, as you say and as I showed, x[1] an be shown to contain 'null'.

My issue in debugging was that the array could contain blank - i.e., "" -  elements, so a display of ',,' wasn't helping me.

I'll mark this as 'Assumed Closed', as I guess its a 'feature'.

[Kukurykus]

Good point about problem with distingishing null from '' in this case. The only what can be done is: $.writeln(x.toSource())