JSFiddle - React, Tailwind, and code Playground

HTML

<script src="http://underscorejs.org/underscore-min.js"></script>

JavaScript

//open a console to see the results

function test(seq,expected) {
    var res=isSequence(seq);
    if (res===expected)
        console.log( seq.join(',')+" : "+expected+" as expected");
    else
        console.log( seq.join(',')+" : fail");
}

function isSequence(seq) {
    var sorted = ['7','8','9','t','j','q','k','a'], l=seq.length, i, ix;
    if (l===0) return true;

    ix=_.indexOf(sorted, seq[0]);
    if (ix===-1) return false;
    if (ix>sorted.length-l) return false;

    for (i=1;i<l;i++) {
        if ( sorted[ix+i]!==seq[i] )
            return false;
    }
    
    return true;
}

var cards = [{card:'h7'},{card:'c8'},{card:'h9'},{card:'st'}]

test( _.map(cards, function(obj) {
    return obj.card.charAt(1);
}), true );

test(['7','8','9','t'] , true);
test(['j','q','k','a'] , true);
test(['7','8','k','a'] , false);
test(['j','k','7','a'] , false);
test(['k','a','q'] , false);
test(['x'] , false);