cannot set property number of undefined

up vote
1
down vote

favorite

I have a component and try to assign to an object some props. On try no1. I have no err but nothing is displayed on UI and in try no2 I have an error "cannot set property number of undefined".

days: Day = ;

now: Date = new Date();



ngOnInit() {

    this.days = ;



    for (let i = 0; i < this.numberOfDaysCurrentMonth; i++) {

        // try no.1

        this.days.forEach(x => x.number = i);

        this.days.forEach(x => x.weekDay = new Date(this.currentYear, this.currentMonth - 1, i).getDay());

        this.days.forEach(x => x.name = '')



        //try no.2

        this.days[i].number = i;

        this.days[i].weekDay = new Date(this.currentYear, this.currentMonth - 1, i).getDay());

        this.days[i].name = ''

    }

and

export class Day {

    number: number;

    weekDay: number;

    name: string;

}

edited Nov 22 at 14:57

Mathew Berg

24.4k95877

asked Nov 22 at 14:45

celamoet

1621211

1

Where are you ever adding data to this.days?
– user2263572
Nov 22 at 14:47

2

this.days[i] will always be undefined, since the days array is never populated.
– briosheje
Nov 22 at 14:47

add a comment |

up vote
1
down vote

favorite

I have a component and try to assign to an object some props. On try no1. I have no err but nothing is displayed on UI and in try no2 I have an error "cannot set property number of undefined".

days: Day = ;

now: Date = new Date();



ngOnInit() {

    this.days = ;



    for (let i = 0; i < this.numberOfDaysCurrentMonth; i++) {

        // try no.1

        this.days.forEach(x => x.number = i);

        this.days.forEach(x => x.weekDay = new Date(this.currentYear, this.currentMonth - 1, i).getDay());

        this.days.forEach(x => x.name = '')



        //try no.2

        this.days[i].number = i;

        this.days[i].weekDay = new Date(this.currentYear, this.currentMonth - 1, i).getDay());

        this.days[i].name = ''

    }

and

export class Day {

    number: number;

    weekDay: number;

    name: string;

}

edited Nov 22 at 14:57

Mathew Berg

24.4k95877

asked Nov 22 at 14:45

celamoet

1621211

1

Where are you ever adding data to this.days?
– user2263572
Nov 22 at 14:47

2

this.days[i] will always be undefined, since the days array is never populated.
– briosheje
Nov 22 at 14:47

add a comment |

up vote
1
down vote

favorite

I have a component and try to assign to an object some props. On try no1. I have no err but nothing is displayed on UI and in try no2 I have an error "cannot set property number of undefined".

days: Day = ;

now: Date = new Date();



ngOnInit() {

    this.days = ;



    for (let i = 0; i < this.numberOfDaysCurrentMonth; i++) {

        // try no.1

        this.days.forEach(x => x.number = i);

        this.days.forEach(x => x.weekDay = new Date(this.currentYear, this.currentMonth - 1, i).getDay());

        this.days.forEach(x => x.name = '')



        //try no.2

        this.days[i].number = i;

        this.days[i].weekDay = new Date(this.currentYear, this.currentMonth - 1, i).getDay());

        this.days[i].name = ''

    }

and

export class Day {

    number: number;

    weekDay: number;

    name: string;

}

edited Nov 22 at 14:57

Mathew Berg

24.4k95877

asked Nov 22 at 14:45

celamoet

1621211

I have a component and try to assign to an object some props. On try no1. I have no err but nothing is displayed on UI and in try no2 I have an error "cannot set property number of undefined".

days: Day = ;

now: Date = new Date();



ngOnInit() {

    this.days = ;



    for (let i = 0; i < this.numberOfDaysCurrentMonth; i++) {

        // try no.1

        this.days.forEach(x => x.number = i);

        this.days.forEach(x => x.weekDay = new Date(this.currentYear, this.currentMonth - 1, i).getDay());

        this.days.forEach(x => x.name = '')



        //try no.2

        this.days[i].number = i;

        this.days[i].weekDay = new Date(this.currentYear, this.currentMonth - 1, i).getDay());

        this.days[i].name = ''

    }

and

export class Day {

    number: number;

    weekDay: number;

    name: string;

}

angular

edited Nov 22 at 14:57

Mathew Berg

24.4k95877

asked Nov 22 at 14:45

celamoet

1621211

edited Nov 22 at 14:57

Mathew Berg

24.4k95877

asked Nov 22 at 14:45

celamoet

1621211

edited Nov 22 at 14:57

Mathew Berg

24.4k95877

edited Nov 22 at 14:57

Mathew Berg

24.4k95877

edited Nov 22 at 14:57

Mathew Berg

24.4k95877

asked Nov 22 at 14:45

celamoet

1621211

asked Nov 22 at 14:45

celamoet

1621211

asked Nov 22 at 14:45

celamoet

1621211

1

Where are you ever adding data to this.days?
– user2263572
Nov 22 at 14:47

2

this.days[i] will always be undefined, since the days array is never populated.
– briosheje
Nov 22 at 14:47

add a comment |

1

Where are you ever adding data to this.days?
– user2263572
Nov 22 at 14:47

2

this.days[i] will always be undefined, since the days array is never populated.
– briosheje
Nov 22 at 14:47

Where are you ever adding data to this.days?
– user2263572
Nov 22 at 14:47

this.days[i] will always be undefined, since the days array is never populated.
– briosheje
Nov 22 at 14:47

add a comment |

2 Answers
2

active

oldest

votes

up vote
4
down vote

accepted

What you need to do is add the day to the days array when you loop over this.numberOfDaysCurrentMonth

ngOnInit() {

  this.days = ;



  for (let i = 0; i < this.numberOfDaysCurrentMonth; i++) {

    let day = {

      number: i,

      weekDay: new Date(this.currentYear, this.currentMonth - 1, i).getDay(),

      name: ''

    }

    this.days.push(day);

  }

}

Your try with this.days.forEach doesn't do anything because it loops over each object in the days array which is empty.

Similarly, this.days[i] is really undefined because the array is empty.

edited Nov 22 at 14:57

answered Nov 22 at 14:52

Oram

616116

add a comment |

up vote
0
down vote

Your array is never filled with any entries. this.days.forEach is going to do something for every item in the array, but as the array is empty, i doesn't do anything.

You should populate the array first and then use forEach on it.

answered Nov 22 at 14:50

mika

23714

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%2f53433380%2fcannot-set-property-number-of-undefined%23new-answer', 'question_page');
}
);

Post as a guest

Name

Required, but never shown

2 Answers
2

active

oldest

votes

2 Answers
2

active

oldest

votes

up vote
4
down vote

accepted

What you need to do is add the day to the days array when you loop over this.numberOfDaysCurrentMonth

ngOnInit() {

  this.days = ;



  for (let i = 0; i < this.numberOfDaysCurrentMonth; i++) {

    let day = {

      number: i,

      weekDay: new Date(this.currentYear, this.currentMonth - 1, i).getDay(),

      name: ''

    }

    this.days.push(day);

  }

}

Your try with this.days.forEach doesn't do anything because it loops over each object in the days array which is empty.

Similarly, this.days[i] is really undefined because the array is empty.

edited Nov 22 at 14:57

answered Nov 22 at 14:52

Oram

616116

add a comment |

up vote
4
down vote

accepted

What you need to do is add the day to the days array when you loop over this.numberOfDaysCurrentMonth

ngOnInit() {

  this.days = ;



  for (let i = 0; i < this.numberOfDaysCurrentMonth; i++) {

    let day = {

      number: i,

      weekDay: new Date(this.currentYear, this.currentMonth - 1, i).getDay(),

      name: ''

    }

    this.days.push(day);

  }

}

Your try with this.days.forEach doesn't do anything because it loops over each object in the days array which is empty.

Similarly, this.days[i] is really undefined because the array is empty.

edited Nov 22 at 14:57

answered Nov 22 at 14:52

Oram

616116

add a comment |

up vote
4
down vote

accepted

What you need to do is add the day to the days array when you loop over this.numberOfDaysCurrentMonth

ngOnInit() {

  this.days = ;



  for (let i = 0; i < this.numberOfDaysCurrentMonth; i++) {

    let day = {

      number: i,

      weekDay: new Date(this.currentYear, this.currentMonth - 1, i).getDay(),

      name: ''

    }

    this.days.push(day);

  }

}

Your try with this.days.forEach doesn't do anything because it loops over each object in the days array which is empty.

Similarly, this.days[i] is really undefined because the array is empty.

edited Nov 22 at 14:57

answered Nov 22 at 14:52

Oram

616116

What you need to do is add the day to the days array when you loop over this.numberOfDaysCurrentMonth

ngOnInit() {

  this.days = ;



  for (let i = 0; i < this.numberOfDaysCurrentMonth; i++) {

    let day = {

      number: i,

      weekDay: new Date(this.currentYear, this.currentMonth - 1, i).getDay(),

      name: ''

    }

    this.days.push(day);

  }

}

Your try with this.days.forEach doesn't do anything because it loops over each object in the days array which is empty.

Similarly, this.days[i] is really undefined because the array is empty.

edited Nov 22 at 14:57

answered Nov 22 at 14:52

Oram

616116

edited Nov 22 at 14:57

answered Nov 22 at 14:52

Oram

616116

answered Nov 22 at 14:52

Oram

616116

answered Nov 22 at 14:52

Oram

616116

add a comment |

up vote
0
down vote

Your array is never filled with any entries. this.days.forEach is going to do something for every item in the array, but as the array is empty, i doesn't do anything.

You should populate the array first and then use forEach on it.

answered Nov 22 at 14:50

mika

23714

add a comment |

up vote
0
down vote

Your array is never filled with any entries. this.days.forEach is going to do something for every item in the array, but as the array is empty, i doesn't do anything.

You should populate the array first and then use forEach on it.

answered Nov 22 at 14:50

mika

23714

add a comment |

up vote
0
down vote

Your array is never filled with any entries. this.days.forEach is going to do something for every item in the array, but as the array is empty, i doesn't do anything.

You should populate the array first and then use forEach on it.

answered Nov 22 at 14:50

mika

23714

Your array is never filled with any entries. this.days.forEach is going to do something for every item in the array, but as the array is empty, i doesn't do anything.

You should populate the array first and then use forEach on it.

answered Nov 22 at 14:50

mika

23714

answered Nov 22 at 14:50

mika

23714

answered Nov 22 at 14:50

mika

23714

answered Nov 22 at 14:50

mika

23714

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