JavaScript 使用循环语句查找通讯录
方法一：
//Setup
var contacts = [
{
"firstName": "Akira",
"lastName": "Laine",
"number": "0543236543",
"likes": ["Pizza", "Coding", "Brownie Points"]
},
{
"firstName": "Harry",
"lastName": "Potter",
"number": "0994372684",
"likes": ["Hogwarts", "Magic", "Hagrid"]
},
{
"firstName": "Sherlock",
"lastName": "Holmes",
"number": "0487345643",
"likes": ["Intriguing Cases", "Violin"]
},
{
"firstName": "Kristian",
"lastName": "Vos",
"number": "unknown",
"likes": ["Javascript", "Gaming", "Foxes"]
}
];
function lookUp(firstName, prop){
// Only change code below this line
var hasName=false;
var hasProp=false;
for(var i in contacts){
if(firstName == contacts[i].firstName){
hasName=true;
if(contacts[i].hasOwnProperty(prop)){
console.log("_s");
return contacts[i][prop];
}
else{continue;}
}else{continue;}
}
if(!hasName){
return "No such contact";
}
if(!hasProp){
return "No such property";
}
// Only change code above this line
}
// Change these values to test your function
lookUp("Akira", "likes");方法二：
//Setup
var contacts = [
{
"firstName": "Akira",
"lastName": "Laine",
"number": "0543236543",
"likes": ["Pizza", "Coding", "Brownie Points"]
},
{
"firstName": "Harry",
"lastName": "Potter",
"number": "0994372684",
"likes": ["Hogwarts", "Magic", "Hagrid"]
},
{
"firstName": "Sherlock",
"lastName": "Holmes",
"number": "0487345643",
"likes": ["Intriguing Cases", "Violin"]
},
{
"firstName": "Kristian",
"lastName": "Vos",
"number": "unknown",
"likes": ["Javascript", "Gaming", "Foxes"]
}
];
function lookUp(firstName, prop){
// Only change code below this line
for(var i=0;i<contacts.length;i++){
if(contacts[i].firstName===firstName)
return contacts[i][prop]=== undefined ? "No such property" :contacts[i][prop];
}
return "No such contact";
// Only change code above this line
}
// Change these values to test your function
lookUp("Akira", "likes");方法三：
//Setup
var contacts = [
{
"firstName": "Akira",
"lastName": "Laine",
"number": "0543236543",
"likes": ["Pizza", "Coding", "Brownie Points"]
},
{
"firstName": "Harry",
"lastName": "Potter",
"number": "0994372684",
"likes": ["Hogwarts", "Magic", "Hagrid"]
},
{
"firstName": "Sherlock",
"lastName": "Holmes",
"number": "0487345643",
"likes": ["Intriguing Cases", "Violin"]
},
{
"firstName": "Kristian",
"lastName": "Vos",
"number": "unknown",
"likes": ["Javascript", "Gaming", "Foxes"]
}
];
function lookUp(firstName, prop){
// Only change code below this line
for(i=0;i<contacts.length;i++){
if(contacts[i].firstName==firstName){
if(contacts[i].hasOwnProperty(prop)){
return contacts[i][prop];
}
else return "No such property";
}
}
return "No such contact";
// Only change code above this line
}
// Change these values to test your function
lookUp("Akira", "likes");