{var answer;
switch （val）{
case "a":answer="apple";
break;
case "b":answer="bird";
break;
case "c":answer="cat";
break;
default:answer="stuff";}}
var arr = [
[1,2], [3,4], [5,6]
];
for (var i=0; i < arr.length; i++) {
for (var j=0; j < arr[i].length; j++) {
console.log(arr[i][j]);
}
}
var myObj = {
top: "hat",
bottom: "pants"
};
myObj.hasOwnProperty("top");// true
myObj.hasOwnProperty("middle"); // false
for(var i=0; i<contacts.length; i++){
if(contacts[i].firstName==firstName){
var a = 1;
if(contacts[i].hasOwnProperty(prop)){
var b=1;
return contacts[i][prop];
}
}
}
if(a!=1){
return "No such contact";
}
if(b!=1){
return "No such property";
}
}
for(var a=0;a<contacts.length;a++){
if(firstName == contacts[a]["firstName"]){
if(contacts[a][prop] != undefined){
return contacts[a][prop];
}else{
return "No such property";
}
}
}return "No such contact";
队列
var a=new Array(1,2,3);
a.push(4);
console.log(a);//[1, 2, 3, 4]
console.log(a.length);//4
console.log(a.pop(a));//4
console.log(a); //[1, 2, 3]
console.log(a.length);//3
(毫无进展)