Keep count of jquery function actions

-2

I have the following jquery function

function checkIfAnyExist() { //new input

    var number = 0;

    if ($(this).length) {

      var number = number + 1;

    }

    console.log(number);

}

Which i call using:

$("#myTable tr:not(.discarded,.old) td:nth-child(1)").each(checkIfAnyExist);

However this code doesn't work as expected as for every row number is reset. I tried taking var number = 0 out and putting it above call function but that didn't work either.

Any ideas?

Thanks

asked Jan 3 at 1:45

Uskompuf

947

2

Can you maybe take a step back and explain why you need this counter? I worry this may be an XY problem. If you're trying to count the elements, you simply need .length. (Not to mention, $(this).length in your example will always return 1, thus true)

– Tyler Roper
Jan 3 at 1:49

1

Btw, don't try to declare variable names more than once

– CertainPerformance
Jan 3 at 1:51

I am trying to check if any rows in my table exist

– Uskompuf
Jan 3 at 1:52

2

Possible duplicate of Is there an "exists" function for jQuery? And in the future, always be sure to explain the bigger picture when asking for help, so you can avoid the XY Problem I mentioned above. :)

– Tyler Roper
Jan 3 at 1:54

1

@Uskompuf If your selector finds 10 rows, then .length will return 10. By doing if ($("selector").length), it will return false if there are none, or true if there are one or more.

– Tyler Roper
Jan 3 at 1:57

|
show 1 more comment

-2

I have the following jquery function

function checkIfAnyExist() { //new input

    var number = 0;

    if ($(this).length) {

      var number = number + 1;

    }

    console.log(number);

}

Which i call using:

$("#myTable tr:not(.discarded,.old) td:nth-child(1)").each(checkIfAnyExist);

However this code doesn't work as expected as for every row number is reset. I tried taking var number = 0 out and putting it above call function but that didn't work either.

Any ideas?

Thanks

asked Jan 3 at 1:45

Uskompuf

947

2

Can you maybe take a step back and explain why you need this counter? I worry this may be an XY problem. If you're trying to count the elements, you simply need .length. (Not to mention, $(this).length in your example will always return 1, thus true)

– Tyler Roper
Jan 3 at 1:49

1

Btw, don't try to declare variable names more than once

– CertainPerformance
Jan 3 at 1:51

I am trying to check if any rows in my table exist

– Uskompuf
Jan 3 at 1:52

2

Possible duplicate of Is there an "exists" function for jQuery? And in the future, always be sure to explain the bigger picture when asking for help, so you can avoid the XY Problem I mentioned above. :)

– Tyler Roper
Jan 3 at 1:54

1

@Uskompuf If your selector finds 10 rows, then .length will return 10. By doing if ($("selector").length), it will return false if there are none, or true if there are one or more.

– Tyler Roper
Jan 3 at 1:57

|
show 1 more comment

-2

I have the following jquery function

function checkIfAnyExist() { //new input

    var number = 0;

    if ($(this).length) {

      var number = number + 1;

    }

    console.log(number);

}

Which i call using:

$("#myTable tr:not(.discarded,.old) td:nth-child(1)").each(checkIfAnyExist);

However this code doesn't work as expected as for every row number is reset. I tried taking var number = 0 out and putting it above call function but that didn't work either.

Any ideas?

Thanks

asked Jan 3 at 1:45

Uskompuf

947

I have the following jquery function

function checkIfAnyExist() { //new input

    var number = 0;

    if ($(this).length) {

      var number = number + 1;

    }

    console.log(number);

}

Which i call using:

$("#myTable tr:not(.discarded,.old) td:nth-child(1)").each(checkIfAnyExist);

However this code doesn't work as expected as for every row number is reset. I tried taking var number = 0 out and putting it above call function but that didn't work either.

Any ideas?

Thanks

javascript jquery html

asked Jan 3 at 1:45

Uskompuf

947

asked Jan 3 at 1:45

Uskompuf

947

asked Jan 3 at 1:45

Uskompuf

947

asked Jan 3 at 1:45

Uskompuf

947

asked Jan 3 at 1:45

Uskompuf

947

2

Can you maybe take a step back and explain why you need this counter? I worry this may be an XY problem. If you're trying to count the elements, you simply need .length. (Not to mention, $(this).length in your example will always return 1, thus true)

– Tyler Roper
Jan 3 at 1:49

1

Btw, don't try to declare variable names more than once

– CertainPerformance
Jan 3 at 1:51

I am trying to check if any rows in my table exist

– Uskompuf
Jan 3 at 1:52

2

Possible duplicate of Is there an "exists" function for jQuery? And in the future, always be sure to explain the bigger picture when asking for help, so you can avoid the XY Problem I mentioned above. :)

– Tyler Roper
Jan 3 at 1:54

1

@Uskompuf If your selector finds 10 rows, then .length will return 10. By doing if ($("selector").length), it will return false if there are none, or true if there are one or more.

– Tyler Roper
Jan 3 at 1:57

|
show 1 more comment

2

Can you maybe take a step back and explain why you need this counter? I worry this may be an XY problem. If you're trying to count the elements, you simply need .length. (Not to mention, $(this).length in your example will always return 1, thus true)

– Tyler Roper
Jan 3 at 1:49

1

Btw, don't try to declare variable names more than once

– CertainPerformance
Jan 3 at 1:51

I am trying to check if any rows in my table exist

– Uskompuf
Jan 3 at 1:52

2

Possible duplicate of Is there an "exists" function for jQuery? And in the future, always be sure to explain the bigger picture when asking for help, so you can avoid the XY Problem I mentioned above. :)

– Tyler Roper
Jan 3 at 1:54

1

@Uskompuf If your selector finds 10 rows, then .length will return 10. By doing if ($("selector").length), it will return false if there are none, or true if there are one or more.

– Tyler Roper
Jan 3 at 1:57

Can you maybe take a step back and explain why you need this counter? I worry this may be an XY problem. If you're trying to count the elements, you simply need .length. (Not to mention, $(this).length in your example will always return 1, thus true)

– Tyler Roper
Jan 3 at 1:49

Btw, don't try to declare variable names more than once

– CertainPerformance
Jan 3 at 1:51

I am trying to check if any rows in my table exist

– Uskompuf
Jan 3 at 1:52

Possible duplicate of Is there an "exists" function for jQuery? And in the future, always be sure to explain the bigger picture when asking for help, so you can avoid the XY Problem I mentioned above. :)

– Tyler Roper
Jan 3 at 1:54

@Uskompuf If your selector finds 10 rows, then .length will return 10. By doing if ($("selector").length), it will return false if there are none, or true if there are one or more.

– Tyler Roper
Jan 3 at 1:57

|
show 1 more comment

1 Answer
1

active

oldest

votes

You are declaring the variable twice: once in the function and once more inside the if condition. Both of those definitions reset the variable to zero upon each iteration of the function.

Consider declaring number once, outside the function's scope. That way, it can be incremented each time the function is called.

function checkIfAnyExist() {

  if ($(this).length) {

    number++;

  }

  console.log(number);

}



var number = 0;



$("#myTable tr:not(.discarded,.old) td:nth-child(1)").each(checkIfAnyExist);

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/2.2.4/jquery.min.js"></script>

<table id="myTable">

  <tr><td></td></tr>

  <tr><td></td></tr>

  <tr><td></td></tr>

  <tr><td></td></tr>

  <tr class="discarded"><td></td></tr>

  <tr class="old"><td></td></tr>

</table>

You are then counting the number of "first cell"s in rows that are not .discarded or .old.

As @TylerRoper wisely explained, $(this).length will never be false in this situation; every row passed to the function has a length. So the function does not appear to be useful.

jQuery's .length by itself is a more effective method of counting the appropriate rows:

var rowCount = $("#myTable tr:not(.discarded,.old)").length;

console.log(rowCount ? rowCount + ' rows found.' : 'There are no rows.');

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/2.2.4/jquery.min.js"></script>

<table id="myTable">

  <tr></tr>

  <tr></tr>

  <tr></tr>

  <tr></tr>

  <tr class="discarded"></tr>

  <tr class="old"></tr>

</table>

Note: It might be a different story if you're trying to determine how many rows are not empty, or contain more than one cell, or contain at least one cell with content, or some other more complicated selection.

edited Jan 3 at 2:27

answered Jan 3 at 1:56

showdev

20.1k133352

add a comment |

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1 Answer
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1 Answer
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You are declaring the variable twice: once in the function and once more inside the if condition. Both of those definitions reset the variable to zero upon each iteration of the function.

Consider declaring number once, outside the function's scope. That way, it can be incremented each time the function is called.

function checkIfAnyExist() {

  if ($(this).length) {

    number++;

  }

  console.log(number);

}



var number = 0;



$("#myTable tr:not(.discarded,.old) td:nth-child(1)").each(checkIfAnyExist);

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/2.2.4/jquery.min.js"></script>

<table id="myTable">

  <tr><td></td></tr>

  <tr><td></td></tr>

  <tr><td></td></tr>

  <tr><td></td></tr>

  <tr class="discarded"><td></td></tr>

  <tr class="old"><td></td></tr>

</table>

You are then counting the number of "first cell"s in rows that are not .discarded or .old.

As @TylerRoper wisely explained, $(this).length will never be false in this situation; every row passed to the function has a length. So the function does not appear to be useful.

jQuery's .length by itself is a more effective method of counting the appropriate rows:

var rowCount = $("#myTable tr:not(.discarded,.old)").length;

console.log(rowCount ? rowCount + ' rows found.' : 'There are no rows.');

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/2.2.4/jquery.min.js"></script>

<table id="myTable">

  <tr></tr>

  <tr></tr>

  <tr></tr>

  <tr></tr>

  <tr class="discarded"></tr>

  <tr class="old"></tr>

</table>

edited Jan 3 at 2:27

answered Jan 3 at 1:56

showdev

20.1k133352

add a comment |

You are declaring the variable twice: once in the function and once more inside the if condition. Both of those definitions reset the variable to zero upon each iteration of the function.

Consider declaring number once, outside the function's scope. That way, it can be incremented each time the function is called.

function checkIfAnyExist() {

  if ($(this).length) {

    number++;

  }

  console.log(number);

}



var number = 0;



$("#myTable tr:not(.discarded,.old) td:nth-child(1)").each(checkIfAnyExist);

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/2.2.4/jquery.min.js"></script>

<table id="myTable">

  <tr><td></td></tr>

  <tr><td></td></tr>

  <tr><td></td></tr>

  <tr><td></td></tr>

  <tr class="discarded"><td></td></tr>

  <tr class="old"><td></td></tr>

</table>

You are then counting the number of "first cell"s in rows that are not .discarded or .old.

As @TylerRoper wisely explained, $(this).length will never be false in this situation; every row passed to the function has a length. So the function does not appear to be useful.

jQuery's .length by itself is a more effective method of counting the appropriate rows:

var rowCount = $("#myTable tr:not(.discarded,.old)").length;

console.log(rowCount ? rowCount + ' rows found.' : 'There are no rows.');

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/2.2.4/jquery.min.js"></script>

<table id="myTable">

  <tr></tr>

  <tr></tr>

  <tr></tr>

  <tr></tr>

  <tr class="discarded"></tr>

  <tr class="old"></tr>

</table>

edited Jan 3 at 2:27

answered Jan 3 at 1:56

showdev

20.1k133352

add a comment |

You are declaring the variable twice: once in the function and once more inside the if condition. Both of those definitions reset the variable to zero upon each iteration of the function.

Consider declaring number once, outside the function's scope. That way, it can be incremented each time the function is called.

function checkIfAnyExist() {

  if ($(this).length) {

    number++;

  }

  console.log(number);

}



var number = 0;



$("#myTable tr:not(.discarded,.old) td:nth-child(1)").each(checkIfAnyExist);

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/2.2.4/jquery.min.js"></script>

<table id="myTable">

  <tr><td></td></tr>

  <tr><td></td></tr>

  <tr><td></td></tr>

  <tr><td></td></tr>

  <tr class="discarded"><td></td></tr>

  <tr class="old"><td></td></tr>

</table>

You are then counting the number of "first cell"s in rows that are not .discarded or .old.

As @TylerRoper wisely explained, $(this).length will never be false in this situation; every row passed to the function has a length. So the function does not appear to be useful.

jQuery's .length by itself is a more effective method of counting the appropriate rows:

var rowCount = $("#myTable tr:not(.discarded,.old)").length;

console.log(rowCount ? rowCount + ' rows found.' : 'There are no rows.');

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/2.2.4/jquery.min.js"></script>

<table id="myTable">

  <tr></tr>

  <tr></tr>

  <tr></tr>

  <tr></tr>

  <tr class="discarded"></tr>

  <tr class="old"></tr>

</table>

edited Jan 3 at 2:27

answered Jan 3 at 1:56

showdev

20.1k133352

You are declaring the variable twice: once in the function and once more inside the if condition. Both of those definitions reset the variable to zero upon each iteration of the function.

Consider declaring number once, outside the function's scope. That way, it can be incremented each time the function is called.

function checkIfAnyExist() {

  if ($(this).length) {

    number++;

  }

  console.log(number);

}



var number = 0;



$("#myTable tr:not(.discarded,.old) td:nth-child(1)").each(checkIfAnyExist);

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/2.2.4/jquery.min.js"></script>

<table id="myTable">

  <tr><td></td></tr>

  <tr><td></td></tr>

  <tr><td></td></tr>

  <tr><td></td></tr>

  <tr class="discarded"><td></td></tr>

  <tr class="old"><td></td></tr>

</table>

You are then counting the number of "first cell"s in rows that are not .discarded or .old.

As @TylerRoper wisely explained, $(this).length will never be false in this situation; every row passed to the function has a length. So the function does not appear to be useful.

jQuery's .length by itself is a more effective method of counting the appropriate rows:

var rowCount = $("#myTable tr:not(.discarded,.old)").length;

console.log(rowCount ? rowCount + ' rows found.' : 'There are no rows.');

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/2.2.4/jquery.min.js"></script>

<table id="myTable">

  <tr></tr>

  <tr></tr>

  <tr></tr>

  <tr></tr>

  <tr class="discarded"></tr>

  <tr class="old"></tr>

</table>

function checkIfAnyExist() {

  if ($(this).length) {

    number++;

  }

  console.log(number);

}



var number = 0;



$("#myTable tr:not(.discarded,.old) td:nth-child(1)").each(checkIfAnyExist);

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/2.2.4/jquery.min.js"></script>

<table id="myTable">

  <tr><td></td></tr>

  <tr><td></td></tr>

  <tr><td></td></tr>

  <tr><td></td></tr>

  <tr class="discarded"><td></td></tr>

  <tr class="old"><td></td></tr>

</table>

function checkIfAnyExist() {

  if ($(this).length) {

    number++;

  }

  console.log(number);

}



var number = 0;



$("#myTable tr:not(.discarded,.old) td:nth-child(1)").each(checkIfAnyExist);

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/2.2.4/jquery.min.js"></script>

<table id="myTable">

  <tr><td></td></tr>

  <tr><td></td></tr>

  <tr><td></td></tr>

  <tr><td></td></tr>

  <tr class="discarded"><td></td></tr>

  <tr class="old"><td></td></tr>

</table>

var rowCount = $("#myTable tr:not(.discarded,.old)").length;

console.log(rowCount ? rowCount + ' rows found.' : 'There are no rows.');

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/2.2.4/jquery.min.js"></script>

<table id="myTable">

  <tr></tr>

  <tr></tr>

  <tr></tr>

  <tr></tr>

  <tr class="discarded"></tr>

  <tr class="old"></tr>

</table>

var rowCount = $("#myTable tr:not(.discarded,.old)").length;

console.log(rowCount ? rowCount + ' rows found.' : 'There are no rows.');

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/2.2.4/jquery.min.js"></script>

<table id="myTable">

  <tr></tr>

  <tr></tr>

  <tr></tr>

  <tr></tr>

  <tr class="discarded"></tr>

  <tr class="old"></tr>

</table>

edited Jan 3 at 2:27

answered Jan 3 at 1:56

showdev

20.1k133352

edited Jan 3 at 2:27

answered Jan 3 at 1:56

showdev

20.1k133352

answered Jan 3 at 1:56

showdev

20.1k133352

answered Jan 3 at 1:56

showdev

20.1k133352

add a comment |

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