JavaScript – Update Value for Specific Key in Map

To update value for a specific key in Map in JavaScript, call set() method on this Map and pass the specific key and new value as arguments.

Syntax

The syntax to update the value for a specific key in a Map map using set() method is

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map.set(key, new_value)

Examples

In the following example, we update the value for key 'a' with a new value of 88.

index.html

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<!DOCTYPE html>
<html lang="en">
<body>
    <pre id="output"></pre>
    <script>
        var map1 = new Map([
            ['a', 10],
            ['b', 20]
        ]);

        map1.set('a', 88);

        var displayOutput = '';
        map1.forEach (function(value, key) {
            displayOutput += key + ' - ' + value + '\n';
        });
        document.getElementById('output').innerHTML += displayOutput;
    </script>
</body>
</html>

Conclusion

In this JavaScript Tutorial, we learned how to update the value for a specific key in a Map in JavaScript using set() method, with examples.