Find array A in a multidimensional array B using JavaScript

Question

I need a fast way to find the one array in another.

The following example describes the scenario I have:

I need to find the array A:

var A = ["A0", "B0", "C0", "D2", "E2", "F0", "G2"];

In array B (please note, my B array may hold millions of results):

B[
["X0", "O0", "I0", "Z2", "T2", "L0", "V2"],
["I0", "V2", "O0", "T0", "L4", "X0", "Z3"],
["A0", "B0", "C0", "D2", "E2", "F0", "G2"],
["Z2", "L7", "T0", "I1", "V3", "X0", "O0"],
["Z3", "I1", "O0", "T3", "X0", "L2", "V2"],
["O0", "X0", "I1", "T2", "V0", "Z3", "L2"],
["I0", "Z0", "L7", "X0", "V3", "O0", "T3"],
["L3", "X0", "I1", "O0", "V0", "Z1", "T1"]
];

Is there a function that would either provide me with a true or false statement, or with an actual result which in the above case is: B[2]

Answer 1

If you have no duplicates in the find array, you could use Array#findIndex with Array#every and Array#includes .

 function getIndex(needle, haystack) { return haystack.findIndex(h => needle.every(n => h.includes(n))); } var a = ["A0", "B0", "C0", "D2", "E2", "F0", "G2"], b = [["X0", "O0", "I0", "Z2", "T2", "L0", "V2"], ["I0", "V2", "O0", "T0", "L4", "X0", "Z3"], ["A0", "B0", "C0", "D2", "E2", "F0", "G2"], ["Z2", "L7", "T0", "I1", "V3", "X0", "O0"], ["Z3", "I1", "O0", "T3", "X0", "L2", "V2"], ["O0", "X0", "I1", "T2", "V0", "Z3", "L2"], ["I0", "Z0", "L7", "X0", "V3", "O0", "T3"], ["L3", "X0", "I1", "O0", "V0", "Z1", "T1"]]; console.log(getIndex(a, b)); 

Answer 2

If the order of items in A matters , then use find and JSON.stringify

var aStr = JSON.stringify( A );
var doesExists = !!B.find( s => JSON.stringify( s ) == aStr );

Demo

 var B = [ ["X0", "O0", "I0", "Z2", "T2", "L0", "V2"], ["I0", "V2", "O0", "T0", "L4", "X0", "Z3"], ["A0", "B0", "C0", "D2", "E2", "F0", "G2"], ["Z2", "L7", "T0", "I1", "V3", "X0", "O0"], ["Z3", "I1", "O0", "T3", "X0", "L2", "V2"], ["O0", "X0", "I1", "T2", "V0", "Z3", "L2"], ["I0", "Z0", "L7", "X0", "V3", "O0", "T3"], ["L3", "X0", "I1", "O0", "V0", "Z1", "T1"] ]; var A = ["A0", "B0", "C0", "D2", "E2", "F0", "G2"]; var aStr = JSON.stringify( A ); var doesExists = !!B.find( s => JSON.stringify( s ) == aStr ); console.log( doesExists ); 

And if the order doesn't matter then use sort as first before comparing.

var fnSort = (a,b) => a.localeCompare( b );
var aStr = JSON.stringify( A.sort( fnSort ) );
var doesExists = !!B.find( s => JSON.stringify( s.sort( fnSort ) ) == aStr );

Demo

 var B = [ ["X0", "O0", "I0", "Z2", "T2", "L0", "V2"], ["I0", "V2", "O0", "T0", "L4", "X0", "Z3"], ["A0", "B0", "C0", "D2", "E2", "F0", "G2"], ["Z2", "L7", "T0", "I1", "V3", "X0", "O0"], ["Z3", "I1", "O0", "T3", "X0", "L2", "V2"], ["O0", "X0", "I1", "T2", "V0", "Z3", "L2"], ["I0", "Z0", "L7", "X0", "V3", "O0", "T3"], ["L3", "X0", "I1", "O0", "V0", "Z1", "T1"] ]; var A = ["A0", "B0", "C0", "D2", "E2", "F0", "G2"]; var fnSort = (a,b) => a.localeCompare( b ); var aStr = JSON.stringify( A.sort( fnSort ) ); var doesExists = !!B.find( s => JSON.stringify( s.sort( fnSort ) ) == aStr ); console.log( doesExists ); 

Answer 3

You could use find operator and compare if the array is included in and other array since arrays are objects you can't compare the directly, because they are different instances, to compare them you can try this trick converting them in strings...

 var A = ["A0", "B0", "C0", "D2", "E2", "F0", "G2"]; var B = [ ["X0", "O0", "I0", "Z2", "T2", "L0", "V2"], ["I0", "V2", "O0", "T0", "L4", "X0", "Z3"], ["A0", "B0", "C0", "D2", "E2", "F0", "G2"], ["Z2", "L7", "T0", "I1", "V3", "X0", "O0"], ["Z3", "I1", "O0", "T3", "X0", "L2", "V2"], ["O0", "X0", "I1", "T2", "V0", "Z3", "L2"], ["I0", "Z0", "L7", "X0", "V3", "O0", "T3"], ["L3", "X0", "I1", "O0", "V0", "Z1", "T1"], ["A0", "B0", "C0", "D2", "E2", "F0", "G2"] ]; function isIncluded(element) { return element.toString() == A.toString(); } console.log(B.find(isIncluded)); // 130 

Answer 4

尝试这样的事情

var result = B.filter(function(bArr){ return bArr.length == A.length && bArr.every(function(ele,index){ return ele==A[index]})})