无论操作是什么，我的 JS 计算器一直输出 0。我已经多次检查控制台但没有任何错误，我还检查了我的变量是否是函数但没有。我不确定是否有任何变量与自身交叉引用。我是 JavaScript 的新手。
我的计算器:
var firstNo = 0;
var secondNo = 0;
var currentNo = 0;
var addedNo = 0;
function updateDisplay(nos) {
var screenn = document.getElementById('display');
var scdata = document.getElementById('display').innerHTML;
String(nos);
String(scdata);
screenn.innerHTML = scdata + nos;
if (currentNo==0) {
addedNo = String(firstNo);
addedNo = addedNo + nos;
firstNo = Number(addedNo);
}if (currentNo==1) {
addedNo = String(secondNo);
addedNo = addedNo + nos;
secondNo = Number(addedNo);
}
}
function clearScreen() {
document.getElementById('display').innerHTML = "";
firstNo = 0;
secondNo = 0;
currentNo = 0;
}
function setOperator(opo) {
var operator = opo;
currentNo = currentNo + 1;
document.getElementById('display').innerHTML = "";
}
function calculate() {
if (operator="+") {
document.getElementById('display').innerHTML = firstNo + secondNo;
firstNo = 0;
secondNo = 0;
currentNo = 0;
}if (operator="*") {
document.getElementById('display').innerHTML = firstNo * secondNo;
firstNo = 0;
secondNo = 0;
currentNo = 0;
}if (operator="/") {
document.getElementById('display').innerHTML = firstNo / secondNo;
firstNo = 0;
secondNo = 0;
currentNo = 0;
}if (operator="-") {
document.getElementById('display').innerHTML = firstNo - secondNo;
firstNo = 0;
secondNo = 0;
currentNo = 0;
}
}#keypad {
display: table;
}
.row {
display: table-row;
}
#display {
background-color: yellow;
}<body>
<h1 id='display'></h1>
<div id='keypad'>
<div class='row'>
<button onclick='updateDisplay(1)'>1</button>
<button onclick='updateDisplay(2)'>2</button>
<button onclick='updateDisplay(3)'>3</button>
<button onclick='setOperator("+")'>+</button>
</div>
<div class='row'>
<button onclick='updateDisplay(4)'>4</button>
<button onclick='updateDisplay(5)'>5</button>
<button onclick='updateDisplay(6)'>6</button>
<button onclick='setOperator("-")'>-</button>
</div>
<div class='row'>
<button onclick='updateDisplay(7)'>7</button>
<button onclick='updateDisplay(8)'>8</button>
<button onclick='updateDisplay(9)'>9</button>
<button onclick='setOperator("/")'>/</button>
</div>
<div class='row'>
<button onclick='updateDisplay(".")'>.</button>
<button onclick='updateDisplay(0)'>0</button>
<button onclick='clearScreen()'>X</button>
<button onclick='setOperator("*")'>*</button>
</div>
<div class='row'>
<button onclick='calculate()'>=</button>
</div>
</div>
</body>如有任何帮助，我们将不胜感激。
最佳答案
试试这个修复: - 你需要把 var operator= ""放在主脚本的顶部。 - 您需要将 if(operator={yourOperator}) 更改为 if(operator=={yourOperator})
注意:您犯了一个语法/逻辑错误，即使用“=”而不是“==”或“===”创建一个语法/逻辑错误，另一个逻辑错误使 var“operator”成为本地变量。 下次将“使用严格”放在脚本的顶部；这应该会揭示一些语法错误，就像你的“if(operator="+")”
var firstNo = 0;
var secondNo = 0;
var currentNo = 0;
var addedNo = 0;
//FIRST CHANGE
var operator= ""
function updateDisplay(nos) {
var screenn = document.getElementById('display');
var scdata = document.getElementById('display').innerHTML;
String(nos);
String(scdata);
screenn.innerHTML =scdata + nos;
if (currentNo==0) {
addedNo = String(firstNo);
addedNo = addedNo + nos;
firstNo = Number(addedNo);
}if (currentNo==1) {
addedNo = String(secondNo);
addedNo = addedNo + nos;
secondNo = Number(addedNo);
}
}
function clearScreen() {
document.getElementById('display').innerHTML = "";
firstNo = 0;
secondNo = 0;
currentNo = 0;
}
function setOperator(opo) {
//SECOND CHANGE
operator = opo;
currentNo = currentNo + 1;
document.getElementById('display').innerHTML = "";
}
function calculate() {
//THIRD CHANGE
if (operator =="+") {
document.getElementById('display').innerHTML = parseFloat(firstNo) + parseFloat(secondNo);
console.log(firstNo)
firstNo = 0;
secondNo = 0;
currentNo = 0;
}
//FORTH CHANGE
if (operator =="*") {
document.getElementById('display').innerHTML = firstNo * secondNo;
firstNo = 0;
secondNo = 0;
currentNo = 0;
}
//FITH CHANGE
if (operator =="/") {
document.getElementById('display').innerHTML = firstNo / secondNo;
firstNo = 0;
secondNo = 0;
currentNo = 0;
}
//SIXTH CHANGE
if (operator =="-") {
document.getElementById('display').innerHTML = firstNo - secondNo;
firstNo = 0;
secondNo = 0;
currentNo = 0;
}
}#keypad {
display: table;
}
.row {
display: table-row;
}
#display {
background-color: yellow;
}<body>
<h1 id='display'></h1>
<div id='keypad'>
<div class='row'>
<button onclick='updateDisplay(1)'>1</button>
<button onclick='updateDisplay(2)'>2</button>
<button onclick='updateDisplay(3)'>3</button>
<button onclick='setOperator("+")'>+</button>
</div>
<div class='row'>
<button onclick='updateDisplay(4)'>4</button>
<button onclick='updateDisplay(5)'>5</button>
<button onclick='updateDisplay(6)'>6</button>
<button onclick='setOperator("-")'>-</button>
</div>
<div class='row'>
<button onclick='updateDisplay(7)'>7</button>
<button onclick='updateDisplay(8)'>8</button>
<button onclick='updateDisplay(9)'>9</button>
<button onclick='setOperator("/")'>/</button>
</div>
<div class='row'>
<button onclick='updateDisplay(".")'>.</button>
<button onclick='updateDisplay(0)'>0</button>
<button onclick='clearScreen()'>X</button>
<button onclick='setOperator("*")'>*</button>
</div>
<div class='row'>
<button onclick='calculate()'>=</button>
</div>
</div>
</body>关于javascript - 为什么我的 JavaScript 计算器一直输出 0？，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/47847006/