同學(xué)們幫我看看是哪里出問題了 運(yùn)行后沒有輸出
<!DOCTYPE? HTML>
<html >
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>流程控制語句</title>
<script type="text/javascript">
?var infos=[
???? ['小A','女',21,'大一'],
???? ['小B','男',23,'大三'],
???? ['小C','男',24,'大四'],
???? ['小D','女',21,'大一'],
???? ['小E','女',22,'大四'],
???? ['小F','男',21,'大一'],
???? ['小G','女',22,'大二'],
???? ['小H','女',20,'大三'],
???? ['小I','女',20,'大一'],
???? ['小J','男',20,'大三']
???? ]
?//第一步把之前的數(shù)據(jù)寫成一個(gè)數(shù)組的形式,定義變量為 infos
?for(var i=0;i<10;i++){
??? while(infos[i][1]=='女'){
??? switch(infos[i][3]=='大一')
??? {
??????? case '大一':
??????????? document.write(infos[i][0]);
??????? case '大二':
??????????? document.write(infos[i][0]);
??????? case '大三':
??????????? document.write(infos[i][0]);
??????? case '大四':
??????????? document.write(infos[i][0]);
??????? default：
??????????? document.write("沒有大一的女生");
??? }
??? }
}
</script>
</head>
<body>
</body>
</html>
2016-11-12
var infos=[
? ? ["小A","女",21,"大一"],
? ? ["小B","男",23,"大三"],
? ? ["小C","男",24,"大四"],
? ? ["小D","女",21,"大一"],
? ? ["小E","女",22,"大四"],
? ? ["小F","男",21,"大一"],
? ? ["小G","女",22,"大二"],
? ? ["小H","女",20,"大三"],
? ? ["小I","女",20,"大一"],
? ? ["小J","男",20,"大三"]
? ];
?//第一步把之前的數(shù)據(jù)寫成一個(gè)數(shù)組的形式,定義變量為 infos
for (var i=0;i<infos.length ;i++ ){
if(infos[i][1]=="女"){
switch(infos[i][3]){
case "大一":
document.write(infos[i][0]);break;
}
}
}
原文中 default后面的冒號(hào)是中文符號(hào),應(yīng)該改為英文符號(hào)--:
switch后面的判斷句 infos[i][3]=='大一' ?值的類型只可能是boolean類型(true和false)
字符串應(yīng)該用""而不是''
2016-11-16
var stu=[
? ? ['小A','女',21,'大一'],
? ? ['小B','男',23,'大三'],
? ? ['小C','男',24,'大四'],
? ? ['小D','女',21,'大一'],
? ? ['小E','女',22,'大四'],
? ? ['小F','男',21,'大一'],
? ? ['小G','女',22,'大二'],
? ? ['小H','女',20,'大三'],
? ? ['小I','女',20,'大一'],
? ? ['小J','男',20,'大三'],
]; //第一步把之前的數(shù)據(jù)寫成一個(gè)數(shù)組的形式,定義變量為 infos
?for(var i=0;i<10;i++){
? ? if(stu[i][3]=='大一'&&stu[i][1]=='女'){
? ? ? ? document.write('大一女生：'+stu[i][0]+'<br>')
? ? }
?
?}
2016-11-12
你的while循環(huán)是個(gè)死循環(huán),沒有跳出,會(huì)一直執(zhí)行,來個(gè)if不是好些么,只是條件判斷....每個(gè)case貌似沒有break,會(huì)全部執(zhí)行呀.......