负数索引

fltenwall · fltenwall · commit 97f9641b6f92 · 2021-06-24T17:13:17.000+08:00
diff --git a/数组负数索引.js b/数组负数索引.js
@@ -0,0 +1,18 @@
+function createArray(...element){
+	const handler = {
+		get(target,propKey,receiver){
+			const index = Number(propKey);
+			if(index < 0){
+				propKey = String(target.length + index)
+			}	
+			return Reflect.get(target,propKey,receiver)
+		}
+	}
+
+	let target = [];
+	target.push(...element);
+	return new Proxy(target,handler)
+}
+
+let arr = createArray('a','b','c');
+arr[-2]
