localStorage数组对象-如何检查是否存在对象键值

Question

如何检查ID是否存在于localStorage对象键数组中

我现在正在使用这个，但它不起作用。

if (favorites.includes(theid)) { alert('You Allready Added this Listing'); }

另外，如何将独立的对象数组分离为ID、图像、标题，以使变量

谢谢

下面是完整的代码

function checkfave (theid) {

// get favorites from local storage or empty array
var favorites = JSON.parse(localStorage.getItem('favorites')) || [];
var theimage = $('#theimage'+theid).attr('src');
var thetitle = $('#thetitle'+theid).text();

if (localStorage.getItem('favorites') != null) {
    if (favorites.includes(theid)) { alert('You Allready Added this Listing'); }
}
            
    favorites.push({ID:theid,IMAGE:theimage,TITLE:thetitle});
    localStorage.setItem('favorites', JSON.stringify(favorites));

    alert('You Just Added Listing '+theid+' To Your Favorites');


    //Loop through the Favorites List and display in console (HIDDEN)
    console.clear();

        for (let i = 0; i < favorites.length; i++) { 
            console.log('ID= '+favorites[i].ID+'  IMAGE='+favorites[i].IMAGE+'  TITLE='+favorites[i].TITLE);
        }//for loop
                                                
}

Answer 1

在提出建议后，我找到了解决办法。

我的解决方案是使用favoritesi.ID ==种族隔离在for循环中检查。

最后的代码如下。我很肯定可以用另一种方式来做，但这目前是可行的。

function checkfave (theid) {

var favorites = JSON.parse(localStorage.getItem('favorites')) || [];
var theimage = $('#theimage'+theid).attr('src');
var thetitle = $('#thetitle'+theid).text();
var added=true;

    //Loop through the Favorites List and display in console (HIDDEN)  
    for (let i = 0; i < favorites.length; i++) { 
            
    if ( favorites[i].ID == theid ) { alert('You allready Added Listing '+theid+' To Your Favorites'); var added=false; break; } else {var added=true;}
    
    }//for loop
        
                
        if (added===true) {
            favorites.push({ID:theid,IMAGE:theimage,TITLE:thetitle});
            localStorage.setItem('favorites', JSON.stringify(favorites));
            alert('You Just Added Listing '+theid+' To Your Favorites');
        }


                                                
}