The findIndex() method of JavaScript is used to return the index of the first element in an array, if the condition is passed.
The syntax is as follows −
array.findIndex(function(currentValue, index, arr), thisValue)
Let us now implement the findIndex() method in JavaScript −
Example
<!DOCTYPE html> <html> <body> <h2>Rank</h2> <button onclick="display()">Result</button> <p id="demo"></p> <p>Finding the index of the player with highest rank.</p> <script> var points = [100, 150, 200, 250, 300, 400]; function topRank(points) { return points >= 400; } function display() { document.getElementById("demo").innerHTML = "index = "+points.findIndex(topRank); } </script> </body>
Output
Click “Result” to get the index −
Example
<!DOCTYPE html> <html> <body> <h2>Rank</h2> <button onclick="display()">Result</button> <p id="demo"></p> <p>Finding the index of the player with specific rank points.</p> <script> var points = [100, 150, 200, 250, 300, 400]; function topRank(points) { return points == 200; } function display() { document.getElementById("demo").innerHTML = "index = "+points.findIndex(topRank); } </script> </body>
Output
Above, click the button “Result” −