javascript remove item from array, if an item already existing in array
Question
following adds items to array:
var arrayOptions = [];
function AddToFilterOptionList(mode) {
arrayOptions.push(mode);
}
remove item from array:
function RemoveFromFilterOptionList(mode) {
var index = arrayOptions.indexOf(mode);
if (index !== -1) {
arrayOptions.splice(index, 1);
}}
for example if i call
AddToFilterOptionList('APPLE') - APPLE should be added to array.
If i again call
AddToFilterOptionList('APPLE+FRUIT') - it should remove the the item ' APPLE ' from array arrayOptions and should add APPLE+FRUIT
Any time only one word that starts with APPLE can be in array. How to find the word like 'APPLE' in javascript.
I tried with Match() which returns the matching word. IndexOf() returns 1 only if whole word is match but not start of word.
6 answers
solution1
1 ACCPTED 2015-05-22 05:25:04
Cycle through the Array and then use the startsWith method.
void AddToFilterOptionList(String mode) {
for (i=0; i<arrayOptions.length; i++) {
if (mode.startsWith(arrayOptions[i] == 1)) {
array[i] = mode;
return; // found, so return
}
}
arrayOptions.push(mode); // should only get here if string did not exist.
}
solution2
1 2015-05-22 05:25:55
This will work assuming the 'this+that' pattern is consistent, and that we only care about the starting item.
http://jsbin.com/gefasuqinu/1/edit?js,console
var arr = [];
function remove(item) {
var f = item.split('+')[0];
for (var i = 0, e = arr.length; i < e; i++) {
if (arr[i].split('+')[0] === f) {
arr.splice(i, 1);
break;
}
}
}
function add(item) {
remove(item);
arr.push(item);
}
solution3
1 2015-05-22 05:30:33
UPDATE:
function add (array, fruits) {
var firstFruit = fruits.split('+')[0]
var secondFruit = fruits.split('+')[1]
var found = false
var output = []
output = array.map(function (item) {
if (item.indexOf(firstFruit) > -1) {
found = true
return fruits
}
else return item
})
if (! found) {
array.push(fruits)
}
return output
}
var fruits = []
add(fruits, 'APPLE')
fruits = add(fruits, 'APPLE+GRAPE')
console.log(fruits[0]) // 'APPLE+GRAPE'
fruits = add(fruits, 'APPLE')
console.log(fruits[0]) // 'APPLE'
solution4
1 2015-05-22 05:47:38
You need to split by + characted and then loop over produced array to add/remove all items:
var arrayOptions = []; function AddToFilterOptionList(mode) { mode.split(/\\+/g).forEach(function(el) { var index = arrayOptions.indexOf(el); if (index !== -1) { arrayOptions.splice(index, 1); } else { arrayOptions.push(el); } }); } function RemoveFromFilterOptionList(mode) { var index = arrayOptions.indexOf(mode); if (index !== -1) { arrayOptions.splice(index, 1); } } AddToFilterOptionList('APPLE'); document.write('<p>' + arrayOptions); // expect: APPLE AddToFilterOptionList('APPLE+FRUIT'); document.write('<p>' + arrayOptions); // expect: FRUIT AddToFilterOptionList('APPLE+FRUIT+CARROT'); document.write('<p>' + arrayOptions); // expect: APPLE,CARROT
solution5
1 2015-05-22 06:26:11
Try this, the code is not optimised though :P
<html>
<head>
<script src = "jquery-1.10.2.min.js"></script>
<script type = "text/javascript">
var itemList = [];
function addItem()
{
var item = $('#item').val();
if(item != '' || item != 'undefined')
{
if(itemList.length == 0)
itemList.push(item);
else
{
for(i=0;i<itemList.length;i++)
{
var splittedInputItems = [];
splittedInputItems = item.split("+");
var splittedListItems = [];
splittedListItems = itemList[i].split("+");
if(splittedListItems[0] == splittedInputItems[0])
{
itemList.splice(i,1);
itemList.push(item);
return;
}
}
itemList.push(item);
}
}
}
</script>
</head>
<body>
<input id="item" type = "text"/>
<input type = "button" value="Add" onclick="addItem()">
</body>
</html>
solution6
0 2018-06-21 08:50:26
let items = [1, 2, 3, 2, 4, 5, 2, 7];
let item = 2;
for (let i = 0; i < items.length; i++) {
if (items[i] === item) {
items.splice(i, 1);
i = i - 1;
}
}
If you want to remove the element '2' from items array, it is a way.
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