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<body>

<p>The exec() method returns the matched text if it finds a match, otherwise it returns null.</p>
<p>Click the button to search a string for the character "e".</p>

<button onclick="myFunction()">Try it</button>

<p id="demo"></p>

<script>
function myFunction() {
    var str = "The best things in life are free";
    var patt = new RegExp("e");
    var res = patt.exec(str);
    document.getElementById("demo").innerHTML = res;
}
</script>

</body>
</html>