javscript数组筛选

Posted 2020-09-27

学生信息 定义二维数组的名称
(‘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‘)
要删选出 女 大一的 学生信息
第一种方法
var info = [[‘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‘]];
var num = 0,key = 0;
var infos = new Array();
for(var i=0;i<5;i++){
infos[i] = new Array();
for(var j=0;j<2;j++){
infos[i][j] = info[num];
num++;
if(infos[i][j][3] == "大一"){
document.write(infos[i][j]);
document.write("<br />");
info[key] = infos[i][j];
key++;
}
}
}
document.write("<br/>第二次筛选：<br />")
for(var q = 0;q < key;q++){
if(info[q][1] == "女"){
document.write(info[q]);
document.write("<br />");
}
}
第二种方法
var infos = [
[‘小A‘,‘女‘,21,‘大一‘],
[‘小B‘,‘男‘,23,‘大三‘],
[‘小C‘,‘男‘,24,‘大四‘],
[‘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‘]
];
document.write("the first"+"<br>");
//第一次筛选，找出都是大一的信息
for(var i=0;i<infos.length;i++)
{
if(infos[i][3] == "大一"){
for(var j=0;j<infos[i].length;j++)
document.write(infos[i][j]+" ");
document.write("<br>");}
}

document.write("the second"+"<br>")
//第二次筛选，找出都是女生的信息
for(var i=0;i<infos.length;i++)
{
if(infos[i][1] == "女"){
for(var j=0;j<infos[i].length;j++)
document.write(infos[i][j]+" ");
document.write("<br>");}
}
第三种方法
var infos = [
[‘小A‘,‘女‘,21,‘大一‘],
[‘小B‘,‘男‘,23,‘大三‘],
[‘小C‘,‘男‘,24,‘大四‘],
[‘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(var i = 0; i < infos.length; i++)
{
if(infos[i][3] === "大一" && infos[i][1] ==="女")
{
for(var j=0;j<infos[i].length;j++ )
document.write(infos[i][j]);
document.write("<br>");
}
}