[Term Entry] Dart Map: .updateAll()

content/dart/concepts/map/terms/update-all/update-all.md

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+---
+Title: '.updateAll()'
+Description: 'Updates all values in a map using a provided function.'
+Subjects:
+  - 'Computer Science'
+  - 'Code Foundations'
+Tags:
+  - 'Dart'
+  - 'Data Structures'
+  - 'Methods'
+  - 'Maps'
+CatalogContent:
+  - 'learn-dart'
+  - 'paths/computer-science'
+---
+
+The **`.updateAll()`** method updates every value in a `Map` by applying a function to each key-value pair.
+
+## Syntax
+
+```pseudo
+map.updateAll((key, value) => newValue);
+```
+
+**Parameters:**
+
+- `key`: The current key in the map
+- `value`: The current value associated with the key
+- `newValue`: The value returned by the function, which replaces the existing value
+
+**Return value:**
+
+Returns `void`. The original map is modified in place.
+
+## Example 1: Updating all values in a map
+
+In this example, `.updateAll()` is used to apply a discount to all product prices stored in a map:
+
+```dart
+void main() {
+  Map<String, double> prices = {
+    'Laptop': 1000.0,
+    'Phone': 600.0,
+    'Tablet': 400.0
+  };
+
+  prices.updateAll((item, price) => price * 0.9);
+
+  print(prices);
+}
+```
+
+The output of this code is:
+
+```shell
+{Laptop: 900, Phone: 540, Tablet: 360}
+```
+
+Each value in the map is passed to the update function, and the returned value replaces the original value while keeping the keys unchanged.