sum

Author: liuwenai

README.md

@@ -419,4 +419,8 @@ $("button").click(function(){
 
 ```
 $(selector).load(URL,data,callbacck)
-```
+```
+
+#### Node.js
+
++ Node.js是 JavaScript 语言在服务器端的运行环境（平台）。

sum.js

@@ -0,0 +1,31 @@
+// nums = [2,7,11,15] ,target = 9
+// 2 + 7 = 9
+// [0,1]
+
+
+function sum(arr, target) {
+    const res = []
+    for (let i = 0; i < arr.length; i++) {
+        for (let j = i + 1; j < arr.length; j++) {
+            if (arr[i] + arr[j] === target) {
+                res.push([i, j]);
+            }
+        }
+    }
+    return res
+}
+
+console.log(sum([6, 2, 3, 7, 15], 9))
+
+
+
+// {1:222, 2:123, 5:888}，
+// 请把数据处理为如下结构：[222, 123, null, null, 888, null, null, null, null, null, null, null]
+
+let arr1 = {1:222, 2:123, 5:888}
+const tt = Array.from({length:12}).map((item,index)=> arr1[index+1]||null)
+
+// let obj = {1:222, 2:123, 5:888};
+// const tt = Array.from({length:12},(item,index)=>obj[index+1]||null)
+
+console.log(tt)