Using a addEventListener to call a forEach function

up vote
1
down vote

favorite

So I cant find any sources online that shows an eventListener triggering a function by click that is forEach based I know i'm doing something wrong here so can any one point me to the right direction.

This is my code

document.addEventListener('DOMContentLoaded',function(){



var numbers = [4, 9, 16, 25];



document.querySelector('button').addEventListener('click',numbers.forEach(myFunction))



function myFunction(item, index) {



  //create a new h1 element 

  var newH1 = document.createElement('h1'); 

  //

  

  //Insert content in the h1

  var innerH1 = document.createTextNode(item); 

  //

  

  //Add the text node to the newly created h1

  newH1.appendChild(innerH1);  

  //

  

  //Add the newly created element and its content into the DOM 

  document.body.insertBefore(newH1,document.body.secondChild);

  //

}



});

<button>Click me</button>

edited Nov 22 at 9:44

asked Nov 22 at 9:39

James Dean

604

Add }) to end of code
– Mohammad
Nov 22 at 9:43

What is your expected end result
– Nedko Dimitrov
Nov 22 at 9:43

secondChild isn’t a real thing. The rest looks OK
– Ben West
Nov 22 at 9:46

The problem is, that addEventListener expects a function reference/expression as the second argument, forEach returns undefined, hence no action is executed on a button click. Notice, that the iteration is executed immediately at the time you're attaching the listener.
– Teemu
Nov 22 at 9:50

add a comment |

up vote
1
down vote

favorite

This is my code

document.addEventListener('DOMContentLoaded',function(){



var numbers = [4, 9, 16, 25];



document.querySelector('button').addEventListener('click',numbers.forEach(myFunction))



function myFunction(item, index) {



  //create a new h1 element 

  var newH1 = document.createElement('h1'); 

  //

  

  //Insert content in the h1

  var innerH1 = document.createTextNode(item); 

  //

  

  //Add the text node to the newly created h1

  newH1.appendChild(innerH1);  

  //

  

  //Add the newly created element and its content into the DOM 

  document.body.insertBefore(newH1,document.body.secondChild);

  //

}



});

<button>Click me</button>

edited Nov 22 at 9:44

asked Nov 22 at 9:39

James Dean

604

Add }) to end of code
– Mohammad
Nov 22 at 9:43

What is your expected end result
– Nedko Dimitrov
Nov 22 at 9:43

secondChild isn’t a real thing. The rest looks OK
– Ben West
Nov 22 at 9:46

The problem is, that addEventListener expects a function reference/expression as the second argument, forEach returns undefined, hence no action is executed on a button click. Notice, that the iteration is executed immediately at the time you're attaching the listener.
– Teemu
Nov 22 at 9:50

add a comment |

up vote
1
down vote

favorite

This is my code

document.addEventListener('DOMContentLoaded',function(){



var numbers = [4, 9, 16, 25];



document.querySelector('button').addEventListener('click',numbers.forEach(myFunction))



function myFunction(item, index) {



  //create a new h1 element 

  var newH1 = document.createElement('h1'); 

  //

  

  //Insert content in the h1

  var innerH1 = document.createTextNode(item); 

  //

  

  //Add the text node to the newly created h1

  newH1.appendChild(innerH1);  

  //

  

  //Add the newly created element and its content into the DOM 

  document.body.insertBefore(newH1,document.body.secondChild);

  //

}



});

<button>Click me</button>

edited Nov 22 at 9:44

asked Nov 22 at 9:39

James Dean

604

This is my code

document.addEventListener('DOMContentLoaded',function(){



var numbers = [4, 9, 16, 25];



document.querySelector('button').addEventListener('click',numbers.forEach(myFunction))



function myFunction(item, index) {



  //create a new h1 element 

  var newH1 = document.createElement('h1'); 

  //

  

  //Insert content in the h1

  var innerH1 = document.createTextNode(item); 

  //

  

  //Add the text node to the newly created h1

  newH1.appendChild(innerH1);  

  //

  

  //Add the newly created element and its content into the DOM 

  document.body.insertBefore(newH1,document.body.secondChild);

  //

}



});

<button>Click me</button>

document.addEventListener('DOMContentLoaded',function(){



var numbers = [4, 9, 16, 25];



document.querySelector('button').addEventListener('click',numbers.forEach(myFunction))



function myFunction(item, index) {



  //create a new h1 element 

  var newH1 = document.createElement('h1'); 

  //

  

  //Insert content in the h1

  var innerH1 = document.createTextNode(item); 

  //

  

  //Add the text node to the newly created h1

  newH1.appendChild(innerH1);  

  //

  

  //Add the newly created element and its content into the DOM 

  document.body.insertBefore(newH1,document.body.secondChild);

  //

}



});

<button>Click me</button>

document.addEventListener('DOMContentLoaded',function(){



var numbers = [4, 9, 16, 25];



document.querySelector('button').addEventListener('click',numbers.forEach(myFunction))



function myFunction(item, index) {



  //create a new h1 element 

  var newH1 = document.createElement('h1'); 

  //

  

  //Insert content in the h1

  var innerH1 = document.createTextNode(item); 

  //

  

  //Add the text node to the newly created h1

  newH1.appendChild(innerH1);  

  //

  

  //Add the newly created element and its content into the DOM 

  document.body.insertBefore(newH1,document.body.secondChild);

  //

}



});

<button>Click me</button>

javascript

edited Nov 22 at 9:44

asked Nov 22 at 9:39

James Dean

604

edited Nov 22 at 9:44

asked Nov 22 at 9:39

James Dean

604

edited Nov 22 at 9:44

asked Nov 22 at 9:39

James Dean

604

asked Nov 22 at 9:39

James Dean

604

asked Nov 22 at 9:39

James Dean

604

Add }) to end of code
– Mohammad
Nov 22 at 9:43

What is your expected end result
– Nedko Dimitrov
Nov 22 at 9:43

secondChild isn’t a real thing. The rest looks OK
– Ben West
Nov 22 at 9:46

The problem is, that addEventListener expects a function reference/expression as the second argument, forEach returns undefined, hence no action is executed on a button click. Notice, that the iteration is executed immediately at the time you're attaching the listener.
– Teemu
Nov 22 at 9:50

add a comment |

Add }) to end of code
– Mohammad
Nov 22 at 9:43

What is your expected end result
– Nedko Dimitrov
Nov 22 at 9:43

secondChild isn’t a real thing. The rest looks OK
– Ben West
Nov 22 at 9:46

The problem is, that addEventListener expects a function reference/expression as the second argument, forEach returns undefined, hence no action is executed on a button click. Notice, that the iteration is executed immediately at the time you're attaching the listener.
– Teemu
Nov 22 at 9:50

Add }) to end of code
– Mohammad
Nov 22 at 9:43

What is your expected end result
– Nedko Dimitrov
Nov 22 at 9:43

secondChild isn’t a real thing. The rest looks OK
– Ben West
Nov 22 at 9:46

The problem is, that addEventListener expects a function reference/expression as the second argument, forEach returns undefined, hence no action is executed on a button click. Notice, that the iteration is executed immediately at the time you're attaching the listener.
– Teemu
Nov 22 at 9:50

add a comment |

1 Answer
1

active

oldest

votes

up vote
2
down vote

accepted

You could try to put numbers.forEach(myFunction); to a function inside the event, like this:

document.addEventListener('DOMContentLoaded', function () {



    var numbers = [4, 9, 16, 25];



    document.querySelector('button').addEventListener('click', function () {

        numbers.forEach(myFunction);

    });



    function myFunction(item, index) {



        //create a new h1 element 

        var newH1 = document.createElement('h1');

        //



        //Insert content in the h1

        var innerH1 = document.createTextNode(item);

        //



        //Add the text node to the newly created h1

        newH1.appendChild(innerH1);

        //



        //Add the newly created element and its content into the DOM 

        document.body.insertBefore(newH1, document.body.secondChild);

        //



    }



});

<button>Click me</button>

Syntax:

selector.addEventListener(event, function () {

    // implement...

});

answered Nov 22 at 9:43

Foo

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',
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
});

}
});

draft saved

draft discarded

Sign up or log in

StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});

Post as a guest

Name

Required, but never shown

StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fstackoverflow.com%2fquestions%2f53427865%2fusing-a-addeventlistener-to-call-a-foreach-function%23new-answer', 'question_page');
}
);

Post as a guest

Name

Required, but never shown

1 Answer
1

active

oldest

votes

1 Answer
1

active

oldest

votes

up vote
2
down vote

accepted

You could try to put numbers.forEach(myFunction); to a function inside the event, like this:

document.addEventListener('DOMContentLoaded', function () {



    var numbers = [4, 9, 16, 25];



    document.querySelector('button').addEventListener('click', function () {

        numbers.forEach(myFunction);

    });



    function myFunction(item, index) {



        //create a new h1 element 

        var newH1 = document.createElement('h1');

        //



        //Insert content in the h1

        var innerH1 = document.createTextNode(item);

        //



        //Add the text node to the newly created h1

        newH1.appendChild(innerH1);

        //



        //Add the newly created element and its content into the DOM 

        document.body.insertBefore(newH1, document.body.secondChild);

        //



    }



});

<button>Click me</button>

Syntax:

selector.addEventListener(event, function () {

    // implement...

});

answered Nov 22 at 9:43

Foo

add a comment |

up vote
2
down vote

accepted

You could try to put numbers.forEach(myFunction); to a function inside the event, like this:

document.addEventListener('DOMContentLoaded', function () {



    var numbers = [4, 9, 16, 25];



    document.querySelector('button').addEventListener('click', function () {

        numbers.forEach(myFunction);

    });



    function myFunction(item, index) {



        //create a new h1 element 

        var newH1 = document.createElement('h1');

        //



        //Insert content in the h1

        var innerH1 = document.createTextNode(item);

        //



        //Add the text node to the newly created h1

        newH1.appendChild(innerH1);

        //



        //Add the newly created element and its content into the DOM 

        document.body.insertBefore(newH1, document.body.secondChild);

        //



    }



});

<button>Click me</button>

Syntax:

selector.addEventListener(event, function () {

    // implement...

});

answered Nov 22 at 9:43

Foo

add a comment |

up vote
2
down vote

accepted

You could try to put numbers.forEach(myFunction); to a function inside the event, like this:

document.addEventListener('DOMContentLoaded', function () {



    var numbers = [4, 9, 16, 25];



    document.querySelector('button').addEventListener('click', function () {

        numbers.forEach(myFunction);

    });



    function myFunction(item, index) {



        //create a new h1 element 

        var newH1 = document.createElement('h1');

        //



        //Insert content in the h1

        var innerH1 = document.createTextNode(item);

        //



        //Add the text node to the newly created h1

        newH1.appendChild(innerH1);

        //



        //Add the newly created element and its content into the DOM 

        document.body.insertBefore(newH1, document.body.secondChild);

        //



    }



});

<button>Click me</button>

Syntax:

selector.addEventListener(event, function () {

    // implement...

});

answered Nov 22 at 9:43

Foo

You could try to put numbers.forEach(myFunction); to a function inside the event, like this:

document.addEventListener('DOMContentLoaded', function () {



    var numbers = [4, 9, 16, 25];



    document.querySelector('button').addEventListener('click', function () {

        numbers.forEach(myFunction);

    });



    function myFunction(item, index) {



        //create a new h1 element 

        var newH1 = document.createElement('h1');

        //



        //Insert content in the h1

        var innerH1 = document.createTextNode(item);

        //



        //Add the text node to the newly created h1

        newH1.appendChild(innerH1);

        //



        //Add the newly created element and its content into the DOM 

        document.body.insertBefore(newH1, document.body.secondChild);

        //



    }



});

<button>Click me</button>

Syntax:

selector.addEventListener(event, function () {

    // implement...

});

document.addEventListener('DOMContentLoaded', function () {



    var numbers = [4, 9, 16, 25];



    document.querySelector('button').addEventListener('click', function () {

        numbers.forEach(myFunction);

    });



    function myFunction(item, index) {



        //create a new h1 element 

        var newH1 = document.createElement('h1');

        //



        //Insert content in the h1

        var innerH1 = document.createTextNode(item);

        //



        //Add the text node to the newly created h1

        newH1.appendChild(innerH1);

        //



        //Add the newly created element and its content into the DOM 

        document.body.insertBefore(newH1, document.body.secondChild);

        //



    }



});

<button>Click me</button>

document.addEventListener('DOMContentLoaded', function () {



    var numbers = [4, 9, 16, 25];



    document.querySelector('button').addEventListener('click', function () {

        numbers.forEach(myFunction);

    });



    function myFunction(item, index) {



        //create a new h1 element 

        var newH1 = document.createElement('h1');

        //



        //Insert content in the h1

        var innerH1 = document.createTextNode(item);

        //



        //Add the text node to the newly created h1

        newH1.appendChild(innerH1);

        //



        //Add the newly created element and its content into the DOM 

        document.body.insertBefore(newH1, document.body.secondChild);

        //



    }



});

<button>Click me</button>

answered Nov 22 at 9:43

Foo

answered Nov 22 at 9:43

Foo

answered Nov 22 at 9:43

Foo

answered Nov 22 at 9:43

Foo

add a comment |

draft saved

draft discarded

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.

Some of your past answers have not been well-received, and you're in danger of being blocked from answering.

Please pay close attention to the following guidance:

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.

draft saved

draft discarded

Sign up or log in

StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});

Post as a guest

Name

Required, but never shown

Post as a guest

Name

Required, but never shown

Sign up or log in

StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});

Post as a guest

Name

Required, but never shown

Sign up or log in

StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});

Post as a guest

Name

Required, but never shown

Sign up or log in

StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});

Post as a guest

Name

Required, but never shown

Name

Required, but never shown

Name

Required, but never shown

This page is only for reference, If you need detailed information, please check here

搜尋此網誌

Btukfyl