The task is to find whether an element exists in the visible DOM or not. For that purpose, there is a number of methods used but we’re going to look at few of them.
Example-1: In this example, the element is searched by document.getElementById(‘Id’) and !! is used before selector to get the boolean result.
<!DOCTYPE HTML> < html > < head > < title > JavaScript | Check if element exists in the visible DOM. </ title > </ head > < body style = "text-align:center;" id = "body" > < h1 style = "color:green;" > GeeksForGeeks </ h1 > < p id = "GFG_UP" style="font-size: 15px; font-weight: bold;"> Check if an Element exists in visible DOM </ p > < button onclick = "gfg_Run()" > check </ button > < p id = "GFG_DOWN" style="color:green; font-size: 23px; font-weight: bold;"> </ p > < script > var el_down = document.getElementById("GFG_DOWN"); var id = 'GFG_UP'; function gfg_Run() { var element = !!document.getElementById(id); var ans = ''; if (element) { ans = "Element of id = '" + id + "' exists in visible DOM."; } else { ans = "Element of id = '" + id + "' not exists in visible DOM."; } el_down.innerHTML = ans; } </ script > </ body > </ html > |
Output:
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Before clicking on the button:
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After clicking on the button:
Example-2: In this example, the element is searched by document.getElementsByClassName(‘className’) and length property is used to check whether variable contains results or not.
<!DOCTYPE HTML> < html > < head > < title > JavaScript | Check if element exists in the visible DOM. </ title > </ head > < body style = "text-align:center;" id = "body" > < h1 style = "color:green;" > GeeksForGeeks </ h1 > < p id = "GFG_UP" class = "p" style="font-size: 15px; font-weight: bold;"> Check if an Element exists in visible DOM </ p > < button onclick = "gfg_Run()" > check </ button > < p id = "GFG_DOWN" class = "p" style="color:green; font-size: 23px; font-weight: bold;"> </ p > < script > var el_down = document.getElementById("GFG_DOWN"); var className = 'p'; function gfg_Run() { var element = document.getElementsByClassName(className); var ans = ''; if (element.length > 0) { ans = "Element of className = '" + className + "' exists in visible DOM."; } else { ans = "Element of className = '" + className + "' not exists in visible DOM."; } el_down.innerHTML = ans; } </ script > </ body > </ html > |
Output:
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Before clicking on the button:
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After clicking on the button: