StringEngine charAt

JavaScript performance comparison

Test case created by Jonathan Perry

Preparation code

<script type="text/javascript">

        var FROMHTMLCODE = { 

                        "&#38;": "\u0026"

                },
                FROMHTMLNAME = { 

                        "&amp;": "\u0026"

                },
                X = /\&[\w]+\;|\&\#[\d]+\;|\&+/;

        function charAtA(i, s) {

                var x, m, v, c;

                if (typeof i === "number") {

                        (x = X).lastIndex = i;

                        if (typeof s === "string") {

                                if ((m = x.exec(s)) === null) {

                                        return s ;

                                } else if ((v = m.shift()).length === 1) {

                                        return v ;

                                }

                                return (typeof (c = FROMHTMLNAME[v]) === "string") ? c : (typeof (c = FROMHTMLCODE[v]) === "string") ? c : s ;

                        }

                }

                return null ;

        }

        function charAtB(i, s) {

                var x, m, v, c;

                if (typeof i === "number") {

                        (x = X).lastIndex = i;

                        if (typeof s === "string") {

                                return ((m = x.exec(s)) === null) ? s : ((v = m.shift()).length === 1) ? v : (typeof (c = FROMHTMLNAME[v]) === "string") ? c : (typeof (c = FROMHTMLCODE[v]) === "string") ? c : s ;

                        }

                }

                return null ;

        }

</script>

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Testing in unknown unknown
Test Ops/sec
charAt A
 
s = charAtA(19, "something something & something something");
s = charAtA(19, "something something &amp; something something");
s = charAtA(19, "something something &#38; something something");
 pending…
charAt B
 
s = charAtB(19, "something something & something something");
s = charAtB(19, "something something &amp; something something");
s = charAtB(19, "something something &#38; something something");
 pending…

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