feat: Add JavaScript core exercises and solutions

- Implemented exercises for array high-order methods, memory and execution, switch statements, and final review.
- Added starter and answer files for each exercise to facilitate learning.
- Created a runner HTML file to execute JavaScript code and display console outputs.
- Updated README files to include exercise objectives, tasks, and usage instructions.

03-javascript-core/13-array-high-order-methods/answer.js

@@ -0,0 +1,37 @@
+const scores = [58, 76, 91, 84];
+const students = [
+  { name: "小周", finished: true },
+  { name: "小林", finished: true },
+  { name: "小陈", finished: false },
+];
+
+const scoreLabels = scores.map(function (score) {
+  return `${score}分`;
+});
+
+const passedScores = scores.filter(function (score) {
+  return score >= 60;
+});
+
+const totalScore = scores.reduce(function (total, score) {
+  return total + score;
+}, 0);
+
+const topScore = scores.find(function (score) {
+  return score >= 90;
+});
+
+const hasFailedScore = scores.some(function (score) {
+  return score < 60;
+});
+
+const allFinished = students.every(function (student) {
+  return student.finished === true;
+});
+
+console.log("带单位成绩：", scoreLabels);
+console.log("及格成绩：", passedScores);
+console.log("总分：", totalScore);
+console.log("第一个 90 分以上：", topScore);
+console.log("是否存在不及格：", hasFailedScore);
+console.log("是否全部完成：", allFinished);