<script>
                let orange = "橙汁"
                let apple = "苹果汁"
                let temp
                // 把橙汁赋给temp
                temp = orange
                // 把苹果汁赋给orange
                orange = apple
                // 把apple赋给temp
                apple = temp
                console.log(orange)
                console.log(apple)
            </script>