JS判断两个数组或对象是否相同的方法示例

JSON.stringify([1,2,3].sort()) === JSON.stringify([3,2,1].sort()); //true

[1,2,3].sort().toString() === [3,2,1].sort().toString(); //true

let cmp = ( x, y ) => {
// If both x and y are null or undefined and exactly the same
 if ( x === y ) {
 return true;
 }
// If they are not strictly equal, they both need to be Objects
 if ( ! ( x instanceof Object ) || ! ( y instanceof Object ) ) {
 return false;
 }
//They must have the exact same prototype chain,the closest we can do is
//test the constructor.
 if ( x.constructor !== y.constructor ) {
 return false;
 }
 for ( var p in x ) {
 //Inherited properties were tested using x.constructor === y.constructor
 if ( x.hasOwnProperty( p ) ) {
 // Allows comparing x[ p ] and y[ p ] when set to undefined
 if ( ! y.hasOwnProperty( p ) ) {
 return false;
 }
 // If they have the same strict value or identity then they are equal
 if ( x[ p ] === y[ p ] ) {
 continue;
 }
 // Numbers, Strings, Functions, Booleans must be strictly equal
 if ( typeof( x[ p ] ) !== "object" ) {
 return false;
 }
 // Objects and Arrays must be tested recursively
 if ( ! Object.equals( x[ p ], y[ p ] ) ) {
 return false;
 }
 }
 }
 for ( p in y ) {
 // allows x[ p ] to be set to undefined
 if ( y.hasOwnProperty( p ) && ! x.hasOwnProperty( p ) ) {
 return false;
 }
 }
 return true;
};