What does this expression do in JavaScript?
I saw this code on the internet: http://jsfiddle.net/q9dEB/392/
$(function()
{
$('#txtDate').datepicker({ beforeShowDay:
function(dt)
{
return [dt.getDay() != 0 && dt.getDay() != 6 , ""];
}
});
});
My question is about this part:
return [dt.getDay() != 0 && dt.getDay() != 6 , ""];
Is it like a lambda of a list of comprehension function? I don't understand how it works.
javascript jquery jquery-ui
edited Dec 8 '18 at 9:23
ADyson
24.8k112646
asked Nov 27 '18 at 23:14
MAximyMAximy
6
add a comment |
I saw this code on the internet: http://jsfiddle.net/q9dEB/392/
$(function()
{
$('#txtDate').datepicker({ beforeShowDay:
function(dt)
{
return [dt.getDay() != 0 && dt.getDay() != 6 , ""];
}
});
});
My question is about this part:
return [dt.getDay() != 0 && dt.getDay() != 6 , ""];
Is it like a lambda of a list of comprehension function? I don't understand how it works.
javascript jquery jquery-ui
edited Dec 8 '18 at 9:23
ADyson
24.8k112646
asked Nov 27 '18 at 23:14
MAximyMAximy
6
add a comment |
I saw this code on the internet: http://jsfiddle.net/q9dEB/392/
$(function()
{
$('#txtDate').datepicker({ beforeShowDay:
function(dt)
{
return [dt.getDay() != 0 && dt.getDay() != 6 , ""];
}
});
});
My question is about this part:
return [dt.getDay() != 0 && dt.getDay() != 6 , ""];
Is it like a lambda of a list of comprehension function? I don't understand how it works.
javascript jquery jquery-ui
edited Dec 8 '18 at 9:23
ADyson
24.8k112646
asked Nov 27 '18 at 23:14
MAximyMAximy
6
I saw this code on the internet: http://jsfiddle.net/q9dEB/392/
$(function()
{
$('#txtDate').datepicker({ beforeShowDay:
function(dt)
{
return [dt.getDay() != 0 && dt.getDay() != 6 , ""];
}
});
});
My question is about this part:
return [dt.getDay() != 0 && dt.getDay() != 6 , ""];
Is it like a lambda of a list of comprehension function? I don't understand how it works.
javascript jquery jquery-ui
javascript jquery jquery-ui
edited Dec 8 '18 at 9:23
ADyson
24.8k112646
asked Nov 27 '18 at 23:14
MAximyMAximy
6
edited Dec 8 '18 at 9:23
ADyson
24.8k112646
asked Nov 27 '18 at 23:14
MAximyMAximy
6
edited Dec 8 '18 at 9:23
ADyson
24.8k112646
edited Dec 8 '18 at 9:23
ADyson
24.8k112646
edited Dec 8 '18 at 9:23
ADyson
24.8k112646
24.8k112646
asked Nov 27 '18 at 23:14
MAximyMAximy
6
asked Nov 27 '18 at 23:14
MAximyMAximy
6
asked Nov 27 '18 at 23:14
MAximyMAximy
6
6
add a comment |
add a comment |
1 Answer
1
active
oldest
votes
No, it just returns an array. The first item in the array is the result of evaluating the expression dt.getDay() != 0 && dt.getDay() != 6 which (since it's an expression using the && operator) will either be true or false. The second item in the array is an empty string ("").
So the end result returned will look something like [true, ""].
Longhand, you could write it like this:
var returnVal = ;
var day = dt.getDay();
var result = false;
if (day != 0 && day != 6) result = true;
returnVal.push(result);
returnVal.push("");
return returnVal;
I hope that breakdown helps you to see what each bit of the code in that line is doing.
answered Nov 27 '18 at 23:18
ADysonADyson
24.8k112646
add a comment |
Your Answer
StackExchange.ifUsing("editor", function () {
StackExchange.using("externalEditor", function () {
StackExchange.using("snippets", function () {
StackExchange.snippets.init();
});
});
}, "code-snippets");
StackExchange.ready(function() {
var channelOptions = {
tags: "".split(" "),
id: "1"
};
initTagRenderer("".split(" "), "".split(" "), channelOptions);
StackExchange.using("externalEditor", function() {
// Have to fire editor after snippets, if snippets enabled
if (StackExchange.settings.snippets.snippetsEnabled) {
StackExchange.using("snippets", function() {
createEditor();
});
}
else {
createEditor();
}
});
function createEditor() {
StackExchange.prepareEditor({
heartbeatType: 'answer',
autoActivateHeartbeat: false,
convertImagesToLinks: true,
noModals: true,
showLowRepImageUploadWarning: true,
reputationToPostImages: 10,
bindNavPrevention: true,
postfix: "",
imageUploader: {
brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
allowUrls: true
},
onDemand: true,
discardSelector: ".discard-answer"
,immediatelyShowMarkdownHelp:true
});
}
});
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fstackoverflow.com%2fquestions%2f53509679%2fwhat-does-this-expression-do-in-javascript%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
1 Answer
1
active
oldest
votes
1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
No, it just returns an array. The first item in the array is the result of evaluating the expression dt.getDay() != 0 && dt.getDay() != 6 which (since it's an expression using the && operator) will either be true or false. The second item in the array is an empty string ("").
So the end result returned will look something like [true, ""].
Longhand, you could write it like this:
var returnVal = ;
var day = dt.getDay();
var result = false;
if (day != 0 && day != 6) result = true;
returnVal.push(result);
returnVal.push("");
return returnVal;
I hope that breakdown helps you to see what each bit of the code in that line is doing.
answered Nov 27 '18 at 23:18
ADysonADyson
24.8k112646
add a comment |
No, it just returns an array. The first item in the array is the result of evaluating the expression dt.getDay() != 0 && dt.getDay() != 6 which (since it's an expression using the && operator) will either be true or false. The second item in the array is an empty string ("").
So the end result returned will look something like [true, ""].
Longhand, you could write it like this:
var returnVal = ;
var day = dt.getDay();
var result = false;
if (day != 0 && day != 6) result = true;
returnVal.push(result);
returnVal.push("");
return returnVal;
I hope that breakdown helps you to see what each bit of the code in that line is doing.
answered Nov 27 '18 at 23:18
ADysonADyson
24.8k112646
add a comment |
No, it just returns an array. The first item in the array is the result of evaluating the expression dt.getDay() != 0 && dt.getDay() != 6 which (since it's an expression using the && operator) will either be true or false. The second item in the array is an empty string ("").
So the end result returned will look something like [true, ""].
Longhand, you could write it like this:
var returnVal = ;
var day = dt.getDay();
var result = false;
if (day != 0 && day != 6) result = true;
returnVal.push(result);
returnVal.push("");
return returnVal;
I hope that breakdown helps you to see what each bit of the code in that line is doing.
answered Nov 27 '18 at 23:18
ADysonADyson
24.8k112646
No, it just returns an array. The first item in the array is the result of evaluating the expression dt.getDay() != 0 && dt.getDay() != 6 which (since it's an expression using the && operator) will either be true or false. The second item in the array is an empty string ("").
So the end result returned will look something like [true, ""].
Longhand, you could write it like this:
var returnVal = ;
var day = dt.getDay();
var result = false;
if (day != 0 && day != 6) result = true;
returnVal.push(result);
returnVal.push("");
return returnVal;
I hope that breakdown helps you to see what each bit of the code in that line is doing.
answered Nov 27 '18 at 23:18
ADysonADyson
24.8k112646
answered Nov 27 '18 at 23:18
ADysonADyson
24.8k112646
answered Nov 27 '18 at 23:18
ADysonADyson
24.8k112646
answered Nov 27 '18 at 23:18
ADysonADyson
24.8k112646
24.8k112646
add a comment |
add a comment |
Thanks for contributing an answer to Stack Overflow!
- Please be sure to answer the question. Provide details and share your research!
But avoid …
- Asking for help, clarification, or responding to other answers.
- Making statements based on opinion; back them up with references or personal experience.
To learn more, see our tips on writing great answers.
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fstackoverflow.com%2fquestions%2f53509679%2fwhat-does-this-expression-do-in-javascript%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
