I have this array
var a = [[1,3][2,3],[3,4],[6,7]];
var b =[[1,3],[2,3]];
I want to remove b array from a.
I tried it
var arr = [[1,3],[2,3]];
var b = [1,3];
var arr = arr.filter((el)=> !b.includes(el));
console.log(arr);
but it is returning the same array "arr". It's not removing the array "b" form array "arr".
In case of simplistic use case, where the order of items, number of items, value of items will be same you can try following
var a = [[1,3], [2,3]];
var b =[1,3];
a = a.filter(v=> v.join() !== b.join());
console.log(a);If you want to consider order, number and value, please try following
var a = [[1,3], [2,3]];
var b =[1,3];
// Create a map where key is item and value is its occurence
let bObj = b.reduce((ac, c) => Object.assign(ac, {[c]: (ac[c] || 0) + 1}), {});
a = a.filter(v=> {
// For every value, create a copy of bObj
let temp = {...bObj};
// for every value in item, decrements the value by 1
v.forEach(e => temp[e] = (temp[e] || 0) - 1);
// Get all the values of object
let tempValues = Object.values(temp);
// If all values are 0, then it is an exact match, return false else return true
if(new Set(tempValues).size === 1 && tempValues[0] === 0) return false;
return true;
});
console.log(a);EDIT
var a = [[1,3],[2,3],[3,4],[6,7]];
var b = [[1,3],[2,3]];
// Create a map where key is item and value is its occurence
let bObj = b.map(v => v.reduce((ac, c) => Object.assign(ac, {[c]: (ac[c] || 0) + 1}), {}));
a = a.filter(v=> {
// For every value, create a copy of bObj
let temp = JSON.parse(JSON.stringify(bObj));
// for every value in item, decrements the value by 1
v.forEach(e => temp.forEach(t => t[e] = (t[e] || 0) - 1));
return !temp.some(t => {
// Get all the values of object
let tempValues = Object.values(t);
// If all values are 0, then it is an exact match, return false else return true
return (new Set(tempValues).size === 1 && tempValues[0] === 0)
});
});
console.log(a);
var b =[3,1]; as join() will make it as 3,1 and it is not same as 1,3
You could search fr the index by stringify the inner array and check against the strigified array b. Then check the index and splice.
var a = [[1, 3], [2, 3]],
b = [1, 3],
index = a.findIndex(
(json => inner => JSON.stringify(inner) === json)
(JSON.stringify(b))
);
if (index !== -1) {
a.splice(index, 1);
}
console.log(a);You can first find the index on arr that you want to remove using every() operation then splice() it:
var arr = [[1,3],[2,3]];
var b = [1,3];
var index = arr.findIndex(item => item.every(elem => b.includes(elem)));
arr.splice(index,1);
console.log(arr);
var my_array = ["raj","bob","clreak","kevin","dJ"];
var start_index = 0
var number_of_elements_to_remove = 1;
var removed_elements = my_array.splice(start_index, number_of_elements_to_remove);
