Javascript事件侦听器在错误的元素上工作？

我正在用javascript制作一个计算器。当我点击像add，subtract这样的按钮时，它调用了delete按钮的功能。我的逻辑是先检查id，然后相应地调用函数。即使所有按钮都有不同的id，del id条件代码仍在运行

HTML

AC
DE

x

Javascript

 const text = document.querySelector("#header-text");
    const buttons = document.querySelectorAll(".btn");
    const numbers =['1','2','3','4','5','6','7','8','9','0'];
    const mathFunc =['ac','del','/','*','-','+','.','equal'];

    let displayText ='0';
    const firstLetterZeroReg =/0\b/;

    for(var i=0;i<buttons.length;i++){
        buttons[i].addEventListener('click',function(e){

            let attr = this.getAttribute('id');
            // when you are pressing a number button
            if(numbers.includes(attr)){
                if(attr=="0" && lastLetterOfText() =="0"){
                    //if initially it is zero and you are trying to add more zero. it will stop that
                    return;
                }
                if(displayText.match(firstLetterZeroReg)){// regular expression is used which is not necessary at all. Just lazy to remove it
                    //If initially it is zero and you press the first button zero is erased
                    displayText =attr;
                    UpdateDisplay();
                    return;
                }
                displayText+=attr;
                UpdateDisplay();
            }else{
                //when you are pressing a function button
                // console.log(attr);
                // console.log(displayText);
                if(attr=="ac"){
                    EraseEverything();
                }else if(attr="del"){
                    //removes the last letter typed




                    //PROBLEM IS IN THIS LINE
                    // This line is being called for other attr too





                    Del();
                }else if(attr!=lastLetterOfText()){
                    //merely checks if we are not pressing the same button twice 
                    console.log("this also being called");
                    if(attr==="."){
                        displayText+=attr;
                        console.log(displayText);
                        UpdateDisplay();
                    }
                }else{
                    console.log("SOme other button is pressed");
                }
            }
        })
}

const text=document.querySelector（“标题文本”）；
const buttons=document.queryselectoral（“.btn”）；
常量数=['1'，'2'，'3'，'4'，'5'，'6'，'7'，'8'，'9'，'0']；
常量mathFunc=['ac'、'del'、'/'、'*'、'-'、'+'、'.'相等']；
让displayText='0'；
常量firstLetterZeroReg=/0\b/；
对于（var i=0；i您使用赋值运算符而不是比较运算符

 else if (attr="del")

应该是

 else if (attr=="del")

此
没有指向所讨论的元素。这是一个jQuery问题。您需要使用
e.target
来代替它。谢谢。但是它适用于数字按钮，如1,2,3，而this.getattr可以work@Amy那不是真的
 else if (attr=="del")