经常会有类似开关效果的按钮，显示隐藏

display.gif

<script>
var flag = true;
var getbox = document.getElementById("box");
var trigger = document.getElementById("trigger");
trigger.onclick = function(){
        if(trigger.value == "隐藏"){
            getbox.style.display = "none"
                    trigger.value = "显示";
            }else{
                getbox.style.display = "block";
                    trigger.value = "隐藏";
                }
                
                /*if(flag){
                    getbox.style.display = "none";
                    flag = false;
                }else{
                    getbox.style.display = "block";
                    flag = true;
                }*/
            }
        </script>

一种是通过定义一个布尔值来判断，另一种是通过变换按钮的value来判断，原理相似