JavaScript array.flatMap()

javascriptobject oriented programmingweb developmentfront end technology更新于 2024/8/15 18:20:17

JavaScript 的 array.flatMap() 方法用于将输入的数组元素展平为一个新数组。

语法如下 −

array.flatMap(function callback(current_value, index, Array))

现在让我们在 JavaScript 中实现 array.flatMap() 方法 −

示例

<!DOCTYPE html>
<html>
<body>
   <h2>Ranking Points</h2>
   <p>Is any point equal to 550 from the key-value pairs...</p>
   <button onclick="display()">Result</button>
   <p id="test"></p>
   <script>
      var pointsArr = [10, 20, 30, 40, 50, 60, 70, 80, 90, 1000];
      var res = pointsArr.flatMap(val => [val + 10]).entries();
      for (val of res) {
         document.getElementById("test").innerHTML += val + "<br>";
      }
      function pointsFunc(points) {
         return points == 550;
      }
      function display() {
         document.getElementById("test").innerHTML = pointsArr.some(pointsFunc);
      }
   </script>
</body>
</html>

输出

点击上方的“结果”按钮 −

示例

<!DOCTYPE html>
<html>
<body>
   <h2>Car Variant</h2>
   <button onclick="display()">Result</button>
   <p id="test"></p>
   <script>
      var carid = ["110", "230", "299", "399"];
      var res = carid.flatMap(val => [val + 10]).entries();
      for (val of res) {
         document.getElementById("test").innerHTML += val + "<br>";
      }
      function display() {
         document.getElementById("test").innerHTML = "Array after slicing some elements =    "+carid.slice(1,4);
      }
   </script>
</body>
</html>