Checking if a key exists in a JS object

Question

I have the following JavaScript object   var obj          key1    val       key2    val       key3    val     Is there a way to check if a key exists in the array  similar to this   testArray   jQuery inArray  key1   obj     does not work   Do I have to iterate through the obj like this   jQuery each obj  function key val

User · Answer

Above answers are good  But this is good too and useful    obj  your key       if  your key  not in obj the result -- gt  true   It s good for short style of code special in if statements   if   obj  your key            if  your key  not exist in obj     console log  key not in obj      else          if  your key  exist in obj     console log  key exist in obj        Note  If your key be equal to null or    your  if  statement will be wrong   obj     a        b   null   d    value    obj  a         result --- gt  true  obj  b         result --- gt  true  obj  c         result --- gt  true  obj  d         result --- gt  false   So  best way for checking if a key exists in a obj is  a  in obj

User · Answer

var obj          key1     k1        key2     k2        key3     k3      if   key1  in obj      console log  has key1 in obj                                                                                 To access a child key of another key  var obj          key1    k1        key2    k2        key3    k3        key4              keyF    kf            if   keyF  in obj key4      console log  has keyF in obj

User · Answer

map has key  is the latest ECMAScript 2015   way of checking the existance of a key in a map  Refer to this for complete details

User · Answer

the simplest way is   x000D   x000D  const obj     x000D    a   value of a   x000D    b   value of b   x000D    c   value of c  x000D     x000D   x000D  if obj a   x000D    console log obj a   x000D   else  x000D    console log  obj a does not exist    x000D    x000D   x000D   x000D

User · Answer

Use the in operator   testArray    key1  in obj      Sidenote  What you got there  is actually no jQuery object  but just a plain JavaScript Object

User · Answer

You can try this   const data       name    Test     value  12    if  name  in data       Found   else       Not found

User · Answer

That s not a jQuery object  it s just an object   You can use the hasOwnProperty method to check for a key   if  obj hasOwnProperty  key1

[javascript] Checking if a key exists in a JS object

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