javascript remove item from array, if an item already existing in array

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following adds items to array:

var arrayOptions = [];

function AddToFilterOptionList(mode) {
    arrayOptions.push(mode);
    }

remove item fr

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6条回答

鱼传尺愫

2021-01-25 23:33

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>

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孤城傲影

2021-01-25 23:40

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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说谎

2021-01-25 23:44

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);
}

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Happy的楠姐

2021-01-25 23:50

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.
 }

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忘掉有多难

2021-01-25 23:55

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

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灰色年华

2021-01-25 23:58

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'

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