前面的话

  前面的博文中介绍了对象拷贝，本文将详细介绍数组复制

push

function copyArray(arr){ var result = []; for(var i = 0; i < arr.length; i++){ result.push(arr[i]); } return result;}var obj1=[1,2,3];var obj2=copyArray(obj1);console.log(obj1); //[1,2,3]console.log(obj2); //[1,2,3]obj2.push(4);console.log(obj1); //[1,2,3]console.log(obj2); //[1,2,3,4]

join
  使用该方法的缺点是数组中的项全部变成了字符串形式

function copyArray(arr){ var result = []; result = arr.join().split(','); return result;}var obj1=[1,2,3];var obj2=copyArray(obj1);console.log(obj1); //[1,2,3]console.log(obj2); //['1','2','3']obj2.push(4);console.log(obj1); //[1,2,3]console.log(obj2); //['1','2','3',4]

concat

function copyArray(arr){ var result = []; result = arr.concat(); return result;}var obj1=[1,2,3];var obj2=copyArray(obj1);console.log(obj1); //[1,2,3]console.log(obj2); //[1,2,3]obj2.push(4);console.log(obj1); //[1,2,3]console.log(obj2); //[1,2,3,4]

slice

function copyArray(arr){ var result = []; result = arr.slice(); return result;}var obj1=[1,2,3];var obj2=copyArray(obj1);console.log(obj1); //[1,2,3]console.log(obj2); //[1,2,3]obj2.push(4);console.log(obj1); //[1,2,3]console.log(obj2); //[1,2,3,4]

深拷贝

  以上方法实现的仅是数组的浅拷贝，如果要实现数组的深拷贝，需要使用递归方法

function copyArray(arr,result){ var result = result || []; for(var i = 0; i < arr.length; i++){ if(arr[i] instanceof Array){ result[i] = []; copyArray(arr[i],result[i]); }else{ result[i] = arr[i]; } } return result;}var obj1=[1,2,[3,4]];var obj2=copyArray(obj1);console.log(obj1[2]); //[3,4]console.log(obj2[2]); //[3,4]obj2[2].push(5);console.log(obj1[2]); //[3,4]console.log(obj2[2]); //[3,4,5]