It is working well is there any other better way to remove duplicates from one array if it has elements of another array ?.
<script>
var array1 = new Array("a","b","c","d","e","f");
var array2 = new Array("c","e");
for (var i = 0; i<array2.length; i++) {
var arrlen = array1.length;
for (var j = 0; j<arrlen; j++) {
if (array2[i] == array1[j]) {
array1 = array1.slice(0, j).concat(array1.slice(j+1, arrlen));
}
}
}
alert(array1);
</script>
array1 = array1.filter(function(val) {
return array2.indexOf(val) == -1;
});
Or, with the availability of ES6:
array1 = array1.filter(val => !array2.includes(val));
The trick, for reasons that are beyond me, is to loop the outer loop downwards (i--) and the inner loop upwards (j++).
See the example bellow:
function test() {
var array1 = new Array("a","b","c","d","e","f");
var array2 = new Array("c","e");
for (var i = array1.length - 1; i >= 0; i--) {
for (var j = 0; j < array2.length; j++) {
if (array1[i] === array2[j]) {
array1.splice(i, 1);
}
}
}
console.log(array1)
}
How do I know this? See the below:
for( var i =myArray.length - 1; i>=0; i--){
for( var j=0; j<toRemove.length; j++){
if(myArray[i] === toRemove[j]){
myArray.splice(i, 1);
}
}
}
or
var myArray = [
{name: 'deepak', place: 'bangalore'},
{name: 'chirag', place: 'bangalore'},
{name: 'alok', place: 'berhampur'},
{name: 'chandan', place: 'mumbai'}
];
var toRemove = [
{name: 'deepak', place: 'bangalore'},
{name: 'alok', place: 'berhampur'}
];
for( var i=myArray.length - 1; i>=0; i--){
for( var j=0; j<toRemove.length; j++){
if(myArray[i] && (myArray[i].name === toRemove[j].name)){
myArray.splice(i, 1);
}
}
}
alert(JSON.stringify(myArray));
On that note, would anyone be able to explain why the outer loop needs to be looped downwards (--)?
Good luck!
array1[i].propertyOfThisItem === array2[j].possiblyTheSamePropertyYou can try this
array1 = array1 .filter(val => {
return !array2.find((val2)=>{
// console.log({valueID:val.id+":"+val2.id});
return val.id===val2.id
})
});
Using the Set.prototype Constructor: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Set
let array1 = Array('a', 'b', 'c', 'd', 'e', 'f')
let array2 = Array('c', 'e', 'g')
let concat = array1.concat(array2) // join arrays => [ 'a', 'b', 'c', 'd', 'e', 'f', 'c', 'e', 'g' ]
// Set will filter out duplicates automatically
let set = new Set(concat) // => Set { 'a', 'b', 'c', 'd', 'e', 'f', 'g' }
// Use spread operator to extend Set to an Array
let result = [...set]
console.log(result) // => [ 'a', 'b', 'c', 'd', 'e', 'f', 'g' ]
use Array.splice()
var array1 = ['1', '2', '3', '4', '5'];
var array2 = ['4', '5'];
var index;
for (var i=0; i<array2.length; i++) {
index = array1.indexOf(array2[i]);
if (index > -1) {
array1.splice(index, 1);
}
}
This is my solution to remove duplicate in ES6.
let foundDuplicate = false;
existingOptions.some(existingItem => {
result = result.filter(item => {
if (existingItem.value !== item.value) {
return item;
} else {
foundDuplicate = true;
}
});
return foundDuplicate;
});
I used this approach because in my case I was having array of objects and indexOf was having problem with it.
This my solution
array1 = array1.filter(function(val) {
return array2.indexOf(val.toString()) == -1;
});
.toString() necessary?window.onload = function () {
var array1 = ['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm'];
var array2 = ['c', 'h', 'k'];
var array3 = [];
var SecondarrayIndexcount = 0;
for (var i = 0; i < array1.length; i++) {
for (var j = 0; j < array2.length; j++) {
if (array1[i] !== array2[j]) {
if (SecondarrayIndexcount === (array2.length - 1)) {
array3.push(array1[i]);
SecondarrayIndexcount = 0;
break;
}
SecondarrayIndexcount++;
}
}
}
for (var i in array3) {
alert(array3[i]);
}
}
</script>
