document getelementbyId will return null if element is not defined

Question

In my code  I see this   if  document getElementById  xx     null          do stuff     if xx element is not defined  will this evaluate to true or false    Should I write   if  document getElementById  xx      to be safe

User · Answer

getElementById is defined by DOM Level 1 HTML to return null in the case no element is matched      null is the most explicit form of the check  and probably the best  but there is no non-null falsy value that getElementById can return - you can only get null or an always-truthy Element object  So there s no practical difference here between    null    null or the looser if  document getElementById  xx

User · Answer

Yes it will return null if it s not present you can try this below in the demo  Both will return true  The first elements exists the second doesn t    Demo  Html   lt div id  xx  gt  lt  div gt    Javascript      if  document getElementById  xx     null        console log  it exists         if  document getElementById  xxThisisNotAnElementOnThePage     null        console log  does not exist

User · Answer

console log document getElementById  xx     evaluates to null   document getElementById  xx     null evaluates to false   You should use document getElementById  xx       null as it is a stronger equality check

[javascript] document.getelementbyId will return null if element is not defined?

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