1
2
3
4
56
7
8
9
1011
12
13
14
1516
17
18
19
2021
22
23
24
2526
27
28
29
3031

function is_unicode (vr) {
    // +   original by: Brett Zamir (http://brett-zamir.me)
    // %        note 1: Almost all strings in JavaScript should be Unicode
    // *     example 1: is_unicode('We the peoples of the United Nations...!');
    // *     returns 1: true    if (typeof vr !== 'string') {
        return false;
    }
 
    // If surrogates occur outside of high-low pairs, then this is not Unicode    var arr=[],
        any='([\s\S])',
        highSurrogate='[\uD800-\uDBFF]',
        lowSurrogate='[\uDC00-\uDFFF]',
        highSurrogateBeforeAny = new RegExp(highSurrogate+any, 'g'),        lowSurrogateAfterAny = new RegExp(any+lowSurrogate, 'g'),
        singleLowSurrogate = new RegExp('^'+lowSurrogate+'$'),
        singleHighSurrogate = new RegExp('^'+highSurrogate+'$');
 
    while ((arr = highSurrogateBeforeAny.exec(vr)) !== null) {        if (!arr[1] || !arr[1].match(singleLowSurrogate)) { // If high not followed by low surrogate
            return false;
        }
    }
    while ((arr = lowSurrogateAfterAny.exec(vr)) !== null) {        if (!arr[1] || !arr[1].match(singleHighSurrogate)) { // If low not preceded by high surrogate
            return false;
        }
    }
    return true;}

1

is_unicode('We the peoples of the United Nations...!');

1

true