Breaking within a string statement can be done by the use of a backslash, '', at the end of the first line

Example:

document.write("This is a program");

And if you change to a new line when not within a string statement, then javaScript ignores break in line.

Example:

var x=1, y=2,

z=

x+y;

The above code is perfectly fine, though not advisable as it hampers debugging.