jquery - javascript- check if value of object in array is not exist - Stack Overflow

admin管理员组

文章数量:1410717

I have this simple array with objects and values, but not all objects have same values:

var array = [
    {name: '‏aaa', mobile: '111-111'},
    {name: '‏bbb', mobile: '222-222', adress: '333-333'},
    {name: '‏ccc', mobile: '444-444', adress: '555-555'}
]

the first object doesn't have an address.

so when I tried to append it to html I got undefined word:

jQuery:

$('ul').append(
    '<li>‏'+array[i].name+'</li>'+
    '<li>‏'+array[i].mobile+'</li>'+
    '<li>‏'+array[i].adress+'</li>'+
)}

HTML:

<li>‏‏aaa</li>
<li>‏111-111</li>
<li>‏undefined</li>

<li>‏‏bbb</li>
<li>‏222-222</li>
<li>‏333-333</li>

how can to check if this value not exist then show nothing instead of undefined word?, or even to not show the whole li tag?

JSFiddle DEMO

I have this simple array with objects and values, but not all objects have same values:

var array = [
    {name: '‏aaa', mobile: '111-111'},
    {name: '‏bbb', mobile: '222-222', adress: '333-333'},
    {name: '‏ccc', mobile: '444-444', adress: '555-555'}
]

the first object doesn't have an address.

so when I tried to append it to html I got undefined word:

jQuery:

$('ul').append(
    '<li>‏'+array[i].name+'</li>'+
    '<li>‏'+array[i].mobile+'</li>'+
    '<li>‏'+array[i].adress+'</li>'+
)}

HTML:

<li>‏‏aaa</li>
<li>‏111-111</li>
<li>‏undefined</li>

<li>‏‏bbb</li>
<li>‏222-222</li>
<li>‏333-333</li>

how can to check if this value not exist then show nothing instead of undefined word?, or even to not show the whole li tag?

JSFiddle DEMO

• javascript
• jquery
• html
• arrays

Share Improve this question Follow asked Jul 11, 2014 at 0:45 Ahmad Seraj EddinAhmad Seraj Eddin 17111 silver badge88 bronze badges

Add a ment  | 

6 Answers 6

Sorted by: Reset to default 3

you need to set it's adress still but with ' ' value.

var array = [
    {name: '‏aaa', mobile: '111-111',adress:''},
    {name: '‏bbb', mobile: '222-222', adress: '333-333'},
    {name: '‏ccc', mobile: '444-444', adress: '555-555'}
]

EDIT :

SOLUTION 2

check if array[i].adress is typeof Undefined

function details () {
    if( typeof array[i].adress == "undefined"){
         array[i].adress = '';   
    }
    $('ul').append(
        '<li>‏'+array[i].name+'</li>'+
        '<li>‏'+array[i].mobile+'</li>'+
        '<li>‏'+array[i].adress+'</li>'+
        '<br />'
    );
}

Fiddle updated : Working Demo

Try

var array = [
    {name: '‏aaa', mobile: '111-111'},
    {name: '‏bbb', mobile: '222-222', adress: '333-333'},
    {name: '‏ccc', mobile: '444-444', adress: '555-555'}
];

$.each(array, function(index, value) {
    $.each(value, function(key, val) {
        $("<li>", {
            "text": val
        }).appendTo("ul")
    });
});

jsfiddle http://jsfiddle/guest271314/mU9T5/

JavaScript has an inherent Boolean value, generally known as either truthy or falsy. A unassigned value will return false in an if statement ie if(array[i].adress){ I added a shorthand if statement to your code to fix the problem.

function details () {
$('ul').append(
    '<li>‏'+array[i].name+'</li>'+
    '<li>‏'+array[i].mobile+'</li>'+
    (array[i].adress? '<li>‏'+ array[i].adress +'</li>': '')
);
}

You can use something like this:

function details () {
    $('ul').append(
        '<li>‏'+array[i].name+'</li>'+
        '<li>‏'+array[i].mobile+'</li>'+ 
        (typeof(array[i].adress) === 'undefined' ? '' :
        ('<li>‏'+array[i].adress+'</li>')) +
        '<br />'
    );
}

I used ternary if with the condition that checked whether address property was defined. If not, the entire <li> is omitted.

SQL Fiddle

Waht you are looking for is this: http://jsfiddle/Z7U3r/

• hasOwnProperty : https://developer.mozilla/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/hasOwnProperty

The hasOwnProperty() method returns a boolean indicating whether the object has the specified property.

Hope this fits your needs :)

code

array[i].hasOwnProperty('adress')

check this one

 if (array[i].adress==null)
{
     array[i]['adress'] = 'None';
}
$('ul').append(
    '<li>‏'+array[i].name+'</li>'+
    '<li>‏'+array[i].mobile+'</li>'+
    '<li>‏'+array[i].adress+'</li>'+
    '<br />'
);

本文标签： jqueryjavascript check if value of object in array is not existStack Overflow