我想比较两个数组。。。理想地、有效地。没有什么稀奇古怪的，如果它们是相同的，那就是真的，如果不是，那就是假的。毫不奇怪，比较运算符似乎不起作用。
var a1 = [1,2,3];
var a2 = [1,2,3];
console.log(a1==a2); // Returns false
console.log(JSON.stringify(a1)==JSON.stringify(a2)); // Returns true
JSON对每个数组进行编码，但是否有一种更快或“更好”的方法来简单地比较数组而不必遍历每个值？
当前回答
递归在NESTED数组上工作（&W）：
function ArrEQ(a1,a2){
return(
//:Are both elements arrays?
Array.isArray(a1)&&Array.isArray(a2)
?
//:Yes: Test each entry for equality:
a1.every((v,i)=>(ArrEQ(v,a2[i])))
:
//:No: Simple Comparison:
(a1===a2)
);;
};;
console.log( "Works With Nested Arrays:" );
console.log( ArrEQ(
[1,2,3,[4,5,[6,"SAME/IDENTICAL"]]],
[1,2,3,[4,5,[6,"SAME/IDENTICAL"]]]
));;
console.log( ArrEQ(
[1,2,3,[4,5,[6,"DIFFERENT:APPLES" ]]],
[1,2,3,[4,5,[6,"DIFFERENT:ORANGES"]]]
));;
其他回答
我喜欢将Undercore库用于数组/对象密集型编码项目。。。在Undercore和Lodash中，无论您是比较数组还是对象，它看起来都是这样的：
_.isEqual(array1, array2) // returns a boolean
_.isEqual(object1, object2) // returns a boolean
Undercore is Equal文档Lodash isEqual文档
var a1 = [1,2,3,6];
var a2 = [1,2,3,5];
function check(a, b) {
return (a.length != b.length) ? false :
a.every(function(row, index) {
return a[index] == b[index];
});
}
check(a1, a2);
//////或///////
var a1 = [1,2,3,6];
var a2 = [1,2,3,6];
function check(a, b) {
return (a.length != b.length) ? false :
!(a.some(function(row, index) {
return a[index] != b[index];
}));
}
check(a1, a2)
选择是否比较订单：
function arraysEqual(a1, a2, compareOrder) {
if (a1.length !== a2.length) {
return false;
}
return a1.every(function(value, index) {
if (compareOrder) {
return value === a2[index];
} else {
return a2.indexOf(value) > -1;
}
});
}
递归在NESTED数组上工作（&W）：
function ArrEQ(a1,a2){
return(
//:Are both elements arrays?
Array.isArray(a1)&&Array.isArray(a2)
?
//:Yes: Test each entry for equality:
a1.every((v,i)=>(ArrEQ(v,a2[i])))
:
//:No: Simple Comparison:
(a1===a2)
);;
};;
console.log( "Works With Nested Arrays:" );
console.log( ArrEQ(
[1,2,3,[4,5,[6,"SAME/IDENTICAL"]]],
[1,2,3,[4,5,[6,"SAME/IDENTICAL"]]]
));;
console.log( ArrEQ(
[1,2,3,[4,5,[6,"DIFFERENT:APPLES" ]]],
[1,2,3,[4,5,[6,"DIFFERENT:ORANGES"]]]
));;
易于理解的
type Values = number | string;
/** Not sorted array */
function compare<Values>(a1: Array<Values>, a2: Array<Values>): boolean {
if (a1.length !== a2.length) {
return false;
}
/** Unique values */
const set1 = new Set<Values>(a1);
const set2 = new Set<Values>(a2);
if (set1.size !== set2.size) {
return false;
}
return [...set1].every((value) => [...set2].includes(value));
}
compare([1, 2, 3], [1, 2, 3]); // true
compare([1, 2, 3], [1, 3, 2]); // true
compare([1, 1, 1], [1, 2, 3]); // false
compare([1, 1, 2, 3], [1, 2, 3]); // false
/** Sorted arrays, faster method */
function compareSorted<Values>(a1: Array<Values>, a2: Array<Values>): boolean {
if (a1.length !== a2.length) {
return false;
}
/** Unique values */
const set1 = new Set<Values>(a1);
const set2 = new Set<Values>(a2);
if (set1.size !== set2.size) {
return false;
}
return [...set1].every((value, index) => value === [...set2][index]);
}
compareSorted([1, 2, 3], [1, 2, 3]); // true
compareSorted([1, 2, 3], [1, 3, 2]); // false
compareSorted([1, 1, 1], [1, 2, 3]); // false
compareSorted([1, 1, 2, 3], [1, 2, 3]); // false
