【程式碼筆記】Web-JavaScript-JavaScript 運算子
阿新 • • 發佈：2018-12-17
一，效果圖。
二，程式碼。
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>javascript 運算子</title>
</head>
<body>
<!--javascriptyu運算子-->
<p>惦記按鈕計算</p>
<button onclick="myFunction0()">點選這裡</button>
<p id="demo0"></p>
<script>
function myFunction0() {
y = 5;
z = 2;
x = y + z;
document.getElementById("demo0").innerHTML = x;
}
</script>
<!--用於字串的+運算子-->
<p>點選按鈕建立及增加字串變數</p>
<button onclick="myFunction()">點選這裡</button>
<p id="demo"></p>
<script>
function myFunction() {
txt1 = "What a very";
txt2 = "nice day";
txt3 = txt1 + txt2;
document.getElementById("demo").innerHTML = txt3;
}
</script>
<!--在字串中增加空格-->
<p>點選按鈕建立及增加字串變數。</p>
<button onclick="myFunction1()">點選這裡</button>
<p id="demo1"></p>
<script>
function myFunction1() {
txt1 = "What a very ";
txt2 = "nice day";
txt3 = txt1 + txt2;
document.getElementById("demo1").innerHTML = txt3;
}
</script>
<p>點選按鈕建立及增加字串變數</p>
<button onclick="myFunction2()">點選這裡</button>
<p id="demo2"></p>
<script>
function myFunction2() {
txt1 = "what a very";
txt2 = "nice day";
txt3 = txt1 + " " + txt2;
document.getElementById("demo2").innerHTML = txt3;
}
</script>
<!--對字串和數字進行加法運算-->
<P>點選按鈕建立及增加字串變數</p>
<button onclick="myFunction()">點選這裡</button>
<p id="demo3"></p>
<script>
function myFunction() {
var x = 5 + 5;
var y = "5" + 5;
var z = "hello" + 5;
var demoP = document.getElementById("demo");
demoP.innerHTML = x + "<br>" + y + "<br>" + z;
}
</script>
</body>
</html>
參考資料：《菜鳥教程》