How do I unset an element in an array in javascript

Question

How do I remove the key  bar  from an array foo so that  bar  won t show up in  for key in foo  alert key

User · Answer

This is how I would do it   myArray splice  myArray indexOf  bar     1

User · Answer

there is an important difference between delete and splice  ORIGINAL ARRAY    lt 1 empty item gt    one   lt 3 empty items gt    five    lt 3 empty items gt   nine   AFTER SPLICE  array splice 1 1       lt 4 empty items gt    five    lt 3 empty items gt    nine    AFTER DELETE  delete array 1       lt 5 empty items gt    five    lt 3 empty items gt    nine

User · Answer

Don t use delete as it won t remove an element from an array it will only set it as undefined  which will then not be reflected correctly in the length of the array   If you know the key you should use splice i e   myArray splice key  1     For someone in Steven s position you can try something like this   for  var key in myArray        if  key     bar             myArray splice key  1             or  for  var key in myArray        if  myArray key      bar             myArray splice key  1

User · Answer

delete foo key      D

User · Answer

delete foo key      D

User · Answer

delete foo key      D

User · Answer

An important note  JavaScript Arrays are not associative arrays like those you might be used to from PHP  If your  array key  is a string  you re no longer operating on the contents of an array  Your array is an object  and you re using bracket notation to access the member named  lt key name gt   Thus    var myArray       myArray  bar     true  myArray  foo     true  alert myArray length      returns 0    because you have not added elements to the array  you have only modified myArray s bar and foo members

User · Answer

If you know the key name simply do like this   delete array  key name

User · Answer

there is an important difference between delete and splice  ORIGINAL ARRAY    lt 1 empty item gt    one   lt 3 empty items gt    five    lt 3 empty items gt   nine   AFTER SPLICE  array splice 1 1       lt 4 empty items gt    five    lt 3 empty items gt    nine    AFTER DELETE  delete array 1       lt 5 empty items gt    five    lt 3 empty items gt    nine

User · Answer

http   www internetdoc info javascript-function remove-key-from-array htm  removeKey arrayName key    function removeKey arrayName key     var x   var tmpArray   new Array     for x in arrayName       if x  key    tmpArray x    arrayName x         return tmpArray

User · Answer

If you know the key name simply do like this   delete array  key name

User · Answer

delete foo key      D

User · Answer

An important note  JavaScript Arrays are not associative arrays like those you might be used to from PHP  If your  array key  is a string  you re no longer operating on the contents of an array  Your array is an object  and you re using bracket notation to access the member named  lt key name gt   Thus    var myArray       myArray  bar     true  myArray  foo     true  alert myArray length      returns 0    because you have not added elements to the array  you have only modified myArray s bar and foo members

User · Answer

Don t use delete as it won t remove an element from an array it will only set it as undefined  which will then not be reflected correctly in the length of the array   If you know the key you should use splice i e   myArray splice key  1     For someone in Steven s position you can try something like this   for  var key in myArray        if  key     bar             myArray splice key  1             or  for  var key in myArray        if  myArray key      bar             myArray splice key  1

User · Answer

http   www internetdoc info javascript-function remove-key-from-array htm  removeKey arrayName key    function removeKey arrayName key     var x   var tmpArray   new Array     for x in arrayName       if x  key    tmpArray x    arrayName x         return tmpArray

User · Answer

This is how I would do it   myArray splice  myArray indexOf  bar     1

[javascript] How do I unset an element in an array in javascript?

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