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<html><body><h1>JavaScript Arrays</h1><h2>The concat() Method</h2><p>The concat() method concatenates (joins) two or more arrays:</p><p id="demo"></p><script>const arr1 = [1, 2, [3, 4]];const arr2 = [[5, 6], 7, 8];const arr3 = arr1.concat(arr2); document.getElementById("demo").innerHTML = arr3;</script></body></html>