?? ? ?? ???? ? ?? ??? ????? ? ?????.
?? ???
?? ???? ????? ??? ?? ??? ??? ???? ? ?????.
x=5? ?? ?? ???? ?? ???? ?????.
| Operator | Description | Example |
|---|
| == | isequal to | x==8 is false |
| === | ??(? ? ??) | x===5? true |
| > | ? | x>8? false |
| < | ? ???? ????. | x<8? ???? |
| >= | ? | x>=8? ????? |
| <= | ? | x<=?? ??? ???? 8 is true |
| ?? ?? | ???? ?? ???? ???? ?? ??? ? ??? ?? ??? ?? ? ????. ??: |
if (age<18) document.write("Too young");
?? ???? ???? ?? ? ??? ???????.
?? ???
?? ???? ??? ? ??? ??? ???? ? ?????.
given x = 6 ? y = 3, ?? ?? ?? ???? ?????. 1) is true||
or
(x==5 || y==5) is false
! | not | !(x==y) is true |
?? ???
JavaScript?? ?? ??? ?? ??? ?? ???? ?? ???? ???? ????.
Syntax
variablename=(condition)?value1:value2
Example
?? age? ?? 18?? ?? ?? ??? "age too young"? ?????. ?? ??, ??? ??? "?? ??"? ?????.
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>php中文網(wǎng)(php.cn)</title>
</head>
<body>
<p>點(diǎn)擊按鈕檢測(cè)年齡。</p>
年齡:<input id="age" value="18" />
<p>是否達(dá)到投票年齡?</p>
<button onclick="myFunction()">點(diǎn)擊按鈕</button>
<p id="demo"></p>
<script>
function myFunction()
{
var age,voteable;
age=document.getElementById("age").value;
voteable=(age<18)?"年齡太小":"年齡已達(dá)到";
document.getElementById("demo").innerHTML=voteable;
}
</script>
</body>
</html>????? ???? ??? ???
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>php中文網(wǎng)(php.cn)</title>
</head>
<body>
<p>點(diǎn)擊按鈕檢測(cè)年齡。</p>
年齡:<input id="age" value="18" />
<p>是否達(dá)到投票年齡?</p>
<button onclick="myFunction()">點(diǎn)擊按鈕</button>
<p id="demo"></p>
<script>
function myFunction()
{
var age,voteable;
age=document.getElementById("age").value;
voteable=(age<18)?"年齡太小":"年齡已達(dá)到";
document.getElementById("demo").innerHTML=voteable;
}
</script>
</body>
</html>
?? ????? ????? ? ????. ?? ???? ???? ????. ???? ? ??? ?? ?? ??????~
? ??? ??? ???? ???? ????.
|
