How can I check if string contains characters & whitespace, not just whitespace?

What is the best way to check if a string contains only whitespace?

The string is allowed to contain characters combined with whitespace, but not just whitespace.

Solution 1:

Instead of checking the entire string to see if there's only whitespace, just check to see if there's at least one character of non whitespace:

if (/\S/.test(myString)) {
    // string is not empty and not just whitespace
}

Solution 2:

Simplest answer if your browser supports the trim() function

if (myString && !myString.trim()) {
    //First condition to check if string is not empty
    //Second condition checks if string contains just whitespace
}