error when deleting "<br>"

[hisoka]

when I run this script :

 

 

var counter = 10;
while (counter > 0)
{
document.write (counter + "<br>");
counter--;
}

 

I get : 10 9 8 7 6 5 4 3 2 1

 

however when I delete "<br>" from the script above like this :

 

var counter = 10;
while (counter > 0)
{
document.write (counter + );
counter--;
}

 

an error is engendered : SyntaxError: expected expression, got ')'

 

why when I deleted "<br>" an error is engendered ?

Edited March 10, 2016 by hisoka

[dsonesuk]

Its expecting a text string, variable or number value to follow the plus symbol.

[hisoka]

so the + sign in document.write (counter + "<br>");

 

is for concatenation ?

[dsonesuk]

Yes! If text string follows variable of a numeric value, or a number value on its own, they will all become text and concatenate, else if followed by numeric type, addition will occur.

[hisoka]

thank you