Question

I want to check if the string is not empty (having whitespaces only also counts as empty). How to compose the regular expression in actionscript?

Answer 1

The pattern should be something like /^\s*$/ (for a single line string); ^ and $ represent the start and end of the line and \s* means match zero or more whitespace characters. For example:

var s:String = /* ... */;
var allWhitespaceOrEmpty:RegExp = /^\s*$/;
if (allWhitespaceOrEmpty.test(s))
{
    // is empty or all whitespace
}
else
{
    // is non-empty with at least 1 non-whitespace char
}

Perhaps a simpler way as commenter Alexander Farber points out is to check for any character except a whitespace character, which is matched by \S in regex:

var nonWhitespaceChar:RegExp = /\S/;
if (nonWhitespaceChar.test(s))
{
    // is non-empty with at least 1 non-whitespace char
}