JSは浅いコピーと深いコピーです.
1431 ワード
1.レプリカ(引用タイプのコピーは全部レプリカ)
var arr1 = [1,2,3,4];
arr2 = arr1;
arr2.push(5);
console.log(arr1);//[1,2,3,4,5]
2.対象の浅いコピーfunction copy(obj){
var tempObj = {};
for(var i in obj){
tempObj[i] = obj[i]; //
}
return tempObj
}
var Person = {
name:'person',
skills:['g','s','m']
}
var newPerson = copy(Person);
console.log(Person.skills ) ;//['g','s','m'];
newPerson.skills.push('b');
console.log(Person.skills); // ['g','s','m','b']; ,
console.log(newPerson .skills); // ['g','s','m','b'];
2.対象の深度コピー(浅いコピーをもとに再帰的に呼び出し)function deepCopy(obj, newObj) {
var tempObj= newObj || {};
for (var i in obj) {
if (typeof obj[i] === 'object') {
tempObj[i] = (obj[i].constructor === Array) ? [] : {};
deepCopy(obj[i], tempObj[i]);
} else {
tempObj[i] = obj[i];
}
}
return tempObj;
};
var Person = {
name:'person',
skills:['g','s','m']
}
var newPerson = deepCopy(Person);
console.log(Person.skills ) ;//['g','s','m'];
newPerson.skills.push('b');
console.log(Person.skills); // ['g','s','m'];
console.log(newPerson .skills); // ['g','s','m','b'];