Jquery – 简单数组，如果它已经存在则推送项目，如果它存在则移除项目

我正在构建一个简单的过滤系统，我只想在一个数组中添加一个字符串，如果已经点击链接就将其删除。 我会尽力解释我能做的最好的事情……

$(document).ready(function(){ //so I start with an empty array var filters []; //when a link is clicked I want to add it to the array.. $('li a', context).click(function(e){ //so I get the value held in the data-event attribute of the clicked item example: "john" newFilter = $(this).attr('data-event'); //this is where I get stuck, I want to test to see if the string I now have //in 'newFilter' is in the array already or not.. if it is in the array I //want to remove it, but if it doesnt exist in the array i want to add it.. if(jQuery.inArray(newFilter, filters){ //add to array } else { //remove from array }; e.preventDefault(); }); }); 

Answer 1

$ .inArray（）返回项目的索引（如果找到），否则返回 -1 （就像indexOf（）一样，支持时）。 因此，你可以这样写：

 var found = jQuery.inArray(newFilter, filters); if (found >= 0) { // Element was found, remove it. filters.splice(found, 1); } else { // Element was not found, add it. filters.push(newFilter); } 

Answer 2

我可能错了，但我相信这就像使用基本的javascript一样简单： _{[ 。 .splice ， .splice ]}

 if($.inArray(newFilter, filters)<0) { //add to array filters.push(newFilter); // <- basic JS see Array.push } else { //remove from array filters.splice($.inArray(newFilter, filters),1); // <- basic JS see Array.splice }; 

当然，如果你真的想要简化它，你可以删除一些行并将其减少为内联编码。

 0 > $.inArray(newFilter,filters) ? filters.push(newFilter) : filters.splice($.inArray(newFilter,filters),1); 

---

对于ABSOLUTE纯JS：

 var i; (i=filters.indexOf(newFilter))<0?filters.push(newFilter):filters.splice(i,1); 

细分：

 var i; // Basic variable to be used if index of item exist // The following is simply an opening to an inline if statement. // It's wrapped in () because we want `i` to equal the index of the item, if found, not what's to follow the `?`. // So this says "If i = an index value less than 0". (i=filters.indexOf(newFilter)) < 0 ? // If it was not found, the index will be -1, thus push new item onto array filters.push(newFilter) : // If found, i will be the index of the item found, so we can now use it to simply splice that item from the array. filters.splice(i,1); 

Answer 3

你可以使用lodash函数“xor”：

 _.xor([2, 1], [2, 3]); // => [1, 3] 

如果您没有数组作为第二个参数，您可以简单地将变量包装到数组中

 var variableToInsertOrRemove = 2; _.xor([2, 1], [variableToInsertOrRemove]); // => [1] _.xor([1, 3], [variableToInsertOrRemove]); // => [1, 2, 3] 

这是doc： https ： //lodash.com/docs/4.16.4#xor

Answer 4

除非您有使用数组的特定原因，否则我建议使用对象。

 $(document).ready(function(){ //so I start with an empty array var filters {}; //when a link is clicked I want to add it to the array.. $('li a', context).click(function(e){ //so I get the value held in the data-event attribute of the clicked item example: "john" newFilter = $(this).attr('data-event'); //this is where I get stuck, I want to test to see if the string I now have //in 'newFilter' is in the array already or not.. if it is in the array I //want to remove it, but if it doesnt exist in the array i want to add it.. if (filters.hasOwnProperty(newFilter)) { // remove from object delete filters[newFilter]; } else { //add to object filters[newFilter] = 'FOO'; // some sentinel since we don't care about value }; e.preventDefault(); }); }); 

Answer 5

我发现的另一种方式：

去掉：

 filters = jQuery.grep(filters, function(value) { return value != newFilter; }); 

加：

 filters.push(newFilter) 

Answer 6

像那样的东西？

 var filters = []; // ... var newFilter = '...'; if(-1 !== (idx = jQuery.inArray(newFilter, filters))) { // remove filters.splice(idx, 1); } else { // add filters.push(newFilter); }