这个for循环和if语句怎么理解，控制台输出的理解不了。

Question

var friends = {    bill: {        firstName: "Bill",        lastName: "Gates",        number: "[phone]",        address: ['dixia']    },    steve: {        firstName: 'Steve',        address: ['tianshang']        }};var search = function(name) {    for(var key in friends) {        if(friends[key].firstName === name) {            console.log(friends[key]);            return friends[key];        }    }};search("Steve");//控制台{ firstName: 'Steve', address: [ 'tianshang' ] }{ firstName: 'Steve', address: [ 'tianshang' ] }{ firstName: 'Steve', address: [ 'tianshang' ] }{ firstName: 'Bill',  lastName: 'Gates',  number: '[phone]',  address: [ 'dixia' ] }{"firstName":"Steve","address":["tianshang"]}

Answer 1

找出与给定参数一致的内容（console.log输出一个，return输出一个）