Filter method

Modern Development/ECMASCript 2021/Server-side ECMAScript 2021 examples/filter/README.md

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+## `filter()` Method
+
+The `filter()` method creates a **new array** with all elements that pass the condition implemented by the provided function.
+
+### Syntax
+
+array.filter((element, index, array) {
+  // return true to keep the element, false otherwise
+});

Modern Development/ECMASCript 2021/Server-side ECMAScript 2021 examples/filter/filter.js

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+// How many times have we written long for-loops just to filter data manually? 
+// The filter() method makes it so much simpler — one clean line to get exactly what you need!
+// Let’s see how we used to do it vs. how clean it can be now.
+
+//before
+(function executeRule(current, previous /*null when async*/) {
+
+	var incidents = [
+		{ number: 'INC001', state: 'In Progress' },
+		{ number: 'INC002', state: 'Resolved' },
+		{ number: 'INC003', state: 'New' },
+		{ number: 'INC004', state: 'In Progress' }
+	];
+
+	var inProgress = [];
+	for (var i = 0; i < incidents.length; i++) {
+		if (incidents[i].state === 'In Progress') {
+			inProgress.push(incidents[i]);
+		}
+	}
+
+	gs.info('In Progress Incidents: ' + JSON.stringify(inProgress));
+
+})(current, previous);
+
+//after
+(function executeRule(current, previous /*null when async*/) {
+
+	var incidents = [
+		{ number: 'INC001', state: 'In Progress' },
+		{ number: 'INC002', state: 'Resolved' },
+		{ number: 'INC003', state: 'New' },
+		{ number: 'INC004', state: 'In Progress' }
+	];
+
+	var inProgress = incidents.filter(inc => inc.state === 'In Progress');
+
+	gs.info('In Progress Incidents: ' + JSON.stringify(inProgress));
+
+})(current, previous);