js中 進(jìn)階4-10編程聯(lián)系
<!DOCTYPE??HTML>
<html?>
<head>
<meta?http-equiv="Content-Type"?content="text/html;?charset=utf-8"?/>
<title>流程控制語(yǔ)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
?var?arr1?=?[];
???var?n?=?0;
???for(var?i=0;i<infos.length;i++){?
????????if(?infos[i][3]?==?"大一"?){??
???????????arr1[n]?=?infos[i];
????????????document.write(arr1[n]+"<br/>");
???????????n=n+1;
????????????
????????}??
???}
???
???document.write("大一人數(shù):?"+arr1.length+"<br/>");??
?//第二次篩選，找出都是女生的信息
??????for(var?i=0;i<arr1.length;i++){?
????????//這里可以用switch??
????????if(arr1[i][1]=='女')
????????{?document.write(arr1[i][0]+"<br/>");}
????}?????
????
?//第一次篩選，找出都是大一的信息
?
??
?//第二次篩選，找出都是女生的信息
?
?
??
</script>
</head>
<body>
</body>
</html>關(guān)于里面的n=n+1 不是太明白他的意思 輸出infos【i】后相當(dāng)于輸出了1個(gè)數(shù)組 既然arr1【n】=infos【i】那么arr1不就是這個(gè)數(shù)組了嗎？
2016-07-06
有四個(gè)人，編號(hào)分別是1、2、3、4，每人給一個(gè)蘋果。先給了一個(gè)給1號(hào)，如果給下一個(gè)人時(shí)，不把編號(hào)加1，不就一直給同一個(gè)人了嗎
2016-07-06
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"]];
for(i=0;i<=10;i++){
if(infos[i][3]=="大一"&&infos[i][1]=="女"){
document.write(infos[i][0]+"<br>")
}
}
2016-07-06
他這個(gè)是將篩選出來(lái)的所有的大一的學(xué)生信息全部存放到另一個(gè)數(shù)組中，就是arr1,相當(dāng)于用所有大一的學(xué)生信息（包括姓名，性別，年齡，年級(jí)）初始化arr1數(shù)組，再在arr1中篩選性別為 女 的學(xué)生的姓名。
2016-07-06
n只是代表數(shù)組的下標(biāo)，也就只是數(shù)組的鍵值。
if(infos[i][3]?==?"大一"){ ????arr1[n]?=?infos[i]; ????document.write(arr1[n]+"<br/>"); ????n=n+1; }n = n + 1的意義在于當(dāng)arr[0] = infos[0]之后將n自加，進(jìn)行下次循環(huán)賦值
arr[1] = infos[3];
2016-07-06
arr1也是個(gè)數(shù)組,它的index=0時(shí),值為arr1[i]的數(shù)組.然后n也是要++的.?實(shí)際arr1也是個(gè)2維數(shù)組.