Append to string variable [closed]

var str = 'blah blah blah';str += ' blah';str += ' ' + 'and some more blah';

var str1 = 'abc';var str2 = str1+' def'; // str2 is now 'abc def'

var str1 = "add";str1 = str1 + " ";

Hope that helps,

CodeHunter