varages=[2,4,6,8,10];functioncheckAdult(age){returnage>=document.getElementById("ageToCheck").value;}functionmyFunction(){document.getElementById("demo").innerHTML=ages.findIndex(checkAdult);} 注意: findIndex() 对于空数组,函数是不会执行的。 findIndex() 并没有改变数组的原始值。 发布者:全栈程序员栈长,转载请注明出处:https...
To find the index of an element in an int array in Java, you can use the indexOf() method of the Arrays class. The indexOf() method returns the index of the first occurrence of the specified element in the array, or -1 if the element is not found. Here is an example of how ...
C# List FindIndexThe FindIndex method returns the zero-based index of the first element that matches the predicate. If no element is found, it returns -1. public int FindIndex(Predicate match); public int FindIndex(int startIndex, Predicate match); public int FindIndex(int startIndex, int...
注释:findIndex() 不会改变原始数组。 代码语言:javascript 代码运行次数:0 获取数组中第一个值等于或大于18的元素的索引:varages=[3,10,18,20];functioncheckAdult(age){returnage>=18;}functionmyFunction(){document.getElementById("demo").innerHTML=ages.findIndex(checkAdult);} 版权声明:本文内容由互联...
Write a program to find the index of the first and last occurrence of a number. Modify the program to return the index using binary search. Write a program to find the closest index where an element could be inserted. Java Code Editor: ...
import java.util.Optional; import java.util.stream.Stream; public class LastElementFinder { public static <T> Optional<T> findLastElement(Stream<T> stream) { return stream.reduce((first, second) -> second); } public static void main(String[] args) { Stream<Integer> stream = Stream.of(...
Previous:Write a Java program to find a specified element in a given sorted array of elements using Exponential search. Next:Write a Java program to find the row, column position of a specified number (row, column position) in a given 2-dimensional array....
In this tutorial, we will discuss how to find the first index of an element in a numpy array. Use thewhere()Function to Find the First Index of an Element in a NumPy Array Thewhere()function from the numpy module is used to return an array that contains the indices of elements that ...
ThefindIndex()method returns the index (position) of the first element that passes a test. ThefindIndex()method returns -1 if no match is found. ThefindIndex()method does not execute the function for empty array elements. ThefindIndex()method does not change the original array. ...
computer book: {0}", ndx); ndx = Books.FindLastIndex(FindComputer); Console.WriteLine("Index of last computer book: {0}", ndx);intmid = Books.Count /2; ndx = Books.FindIndex(mid, mid, FindComputer); Console.WriteLine("Index of first computer book in the second half of the collec...