Inténtalo tú mismo - JavaScript Reference isfinite_number

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<p>The Number.isFinite() function returns true if the value is  a finite, legal number.</p>

<p>Click the button to check whether the values are finite numbers.</p>

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

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

<p><strong>Note:</strong> The Number.isFinite() function is not supported in IE 11 (and earlier versions).</p>

<script>
function myFunction() {
    var res = "";
    res = res + Number.isFinite(123) + ": 123<br>";
    res = res + Number.isFinite(-1.23) + ": -1.23<br>";
    res = res + Number.isFinite(5-2) + ": 5-2<br>";
    res = res + Number.isFinite(0) + ": 0<br>";
    res = res + Number.isFinite('123') + ": '123'<br>";
    res = res + Number.isFinite('Hello') + ": 'Hello'<br>";
    res = res + Number.isFinite('2005/12/12') + ": '2005/12/12'<br>";
    res = res + Number.isFinite(Infinity) + ": Infinity<br>";
    res = res + Number.isFinite(-Infinity) + ": -Infinity<br>";
    res = res + Number.isFinite(0 / 0) + ": 0 / 0<br>";

document.getElementById("demo").innerHTML = res;
}
</script>

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