JavaScript中循环遍历Array与Map的方法小结
js循环数组各种方法
eg1：
for(vari=0;i<myStringArray.length;i++){
alert(myStringArray[i]);
//Dosomething
}
eg2：
Array.prototype.foo="foo!";
vararray=['a','b','c'];
for(variinarray){
alert(array[i]);
}
for(variinthis.$GLOBAL_DETAIL.album_photo_ids){if(this.$GLOBAL_DETAIL.album_photo_ids[i]=="3487675024077108")alert(this.$GLOBAL_DETAIL.album_photo_ids[i]);}
eg3：
[1,2,3,4].map(function(item){
alert(item);
})
eg4：
varx=[1,2,3,4].map(function(item){returnitem*10;});
//Andnowxis[10,20,30,40]
eg5：
varmyStringArray=["Hello","World"]
varlen=myStringArray.length
for(vari=0;i<len;++i){
if(iinmyStringArray){
vars=myStringArray[i];
...dosomethingwiths...
}
}
eg6：
varmyStringArray=["Hello","World"]
myStringArray.forEach(function(s){
...dosomethingwiths...
})
eg7：
vari=0,item,items=['one','two','three'];
while(item=items[i++]){
console.log(item);
}
//logs:'one','two','three'
andforthereverseorder,anevenmoreefficientloop
varitems=['one','two','three'],i=items.length;
while(i--){
console.log(items[i]);
}
//logs:'three','two','one'
ortheclassicalforloop
varitems=['one','two','three']
for(vari=0,l=items.length;i<l;i++){
console.log(items[i]);
}
//logs:'one','two','three'
eg8：
varmyStringArray=['Hello','World'];//arrayuses[]not{}
for(variinmyStringArray){
console.log(i+'->'+myStringArray[i]);//iistheindex/key,nottheitem
}
js循环map，获取所有的key和value
eg1：
//Page地址
pageUrl:{
menu:"loadPage.htm?url=/collect/menu.page",//进入菜单页面
guangfaPage:"loadPage.htm?url=/collect/menu.page",//进入广发信息收集页面
pinganPage:"loadPage.htm?url=/collect/menu.page",//进入平安信息收集页面
nuonuoPage:"loadPage.htm?url=/collect/menu.page",//进入诺诺信息收集页面
youbangPage:"loadPage.htm?url=/collect/menu.page",//进入友邦信息收集页面
inputMobileNo:"loadPage.htm?url=/collect/inputMobileNo.page",//进入输入手机号页面
readIdCard:"loadPage.htm?url=/collect/readIdCard.page",//进入读取身份证页面
member:"loadPage.htm?url=/collect/member.page",//进入输入会员卡号页面
bankCard:"loadPage.htm?url=/collect/bankCard.page",//进入插入银行卡页面
url:"loadPage.htm?url=/collect/url.page"//进入跳转url页面
},
for(varkeyinthis.pageUrl){
alert(key+":"+this.pageUrl[key]);
}
eg2：
varobj={
"a":1,
"b":2,
"c":3
};
for(varpropinobj){
if(obj.hasOwnProperty(prop)){
//orif(Object.prototype.hasOwnProperty.call(obj,prop))forsafety...
alert("prop:"+prop+"value:"+obj[prop])
}
}
双重Map循环
eg：
varmsg="";
for(varkeyinPin){
for(variinPin[key]){
msg+=i+":"+Pin[key][i]+"\n";
}
}
alert(msg);