我正在使用Titanium,我的代码看起来是这样的:

var currentData = new Array();
if(currentData[index]!==""||currentData[index]!==null||currentData[index]!=='null')
{
    Ti.API.info("is exists  " + currentData[index]);
    return true;
}
else
{   
    return false;
}

我传递一个索引到currentData数组。使用上面的代码,我仍然无法检测到不存在的索引。


当前回答

if(typeof arrayName[index] == undefined) {
    console.log("Doesn't exist")
}
else {
console.log("does exist")
}

其他回答

var fruits =["香蕉","橙子","苹果","芒果"]; if(fruit . indexof ("Banana") == -1){ Console.log('项目不存在') }其他{ console.log(“项目存在”) }

这些天,我会利用ecmascript,像这样使用它

return myArr?.[index]
var myArray = ["Banana", "Orange", "Apple", "Mango"];

if (myArray.indexOf(searchTerm) === -1) {
  console.log("element doesn't exist");
}
else {
  console.log("element found");
}

简单的方法来检查项目是否存在

Array.prototype.contains = function(obj) {
    var i = this.length;
    while (i--)
       if (this[i] == obj)
       return true;
    return false;
}

var myArray= ["Banana", "Orange", "Apple", "Mango"];

myArray.contains("Apple")
if(typeof arrayName[index] == undefined) {
    console.log("Doesn't exist")
}
else {
console.log("does exist")
}