1.严格相等(indexOf()、lastIndexOf()、includes()) 这三个方法都接受两个参数(要查找的元素、可选的起始搜索位置)indexOf()、includes()从数组第一项往后搜索,lastIndexOf()从数组最后一项往前开始搜索 indexOf与lastIndexOf返回要查找的元素在数组中的位置,如果没有找到返回-1,incoudes返回布尔值,表示是否至少...
functionisBigEnough(element){returnelement>=15;}[12,5,8,130,44].findIndex(isBigEnough);// index of 4th element in the Array is returned,// so this will result in '3' 另请参见find()方法,它返回数组中找到的元素的值,而不是其索引。
By Index The easiest way to get elements from an array in PostgreSQL is by accessing them using their index. For example: Copy 1 SELECT id, title, genres[1] FROM books; In this query, the genres[1] expression extracts the first element of the genres array from each row: ...
% find() will get the index of element % store it in the index index = find(array==2) 输出: 当数组包含重复值时,find()函数将打印相应元素的所有索引。因此,如果您不想要该元素的所有索引,则可以使用find(X,n)函数。 找到(X,n) 返回X 中元素的前 n 个索引。 例子: MATLAB % MATLAB code for...
The indexOf() method This method returns the index of the first occurrence of matched element in the array. If no element matches, then it returns -1. This method is case-sensitive. constshop=['Amazon','Flipkart','Wallmart','Myntra','Flipkart']; ...
I have an array of non-repeating elements, X. I need to find the index of a specific element, 1.5 in X. I am trying to do index=find(X==1.5). However it just does not work. I gives me a "empty matrix". Does this have to do with the elements in the array being deci...
arr.some(callback(element[, index[, array]])[, thisArg]) 返回值: 数组中有至少一个元素通过回调函数的测试就会返回true;所有元素都没有通过回调函数的测试返回值才会为false。 some() 为数组中的每一个元素执行一次 callback 函数,直到找到一个使得 callback 返回一个“真值”(即可转换为布尔值 true 的值...
测试1:返回数组中第一个大于15的数的index 代码语言:javascript 代码运行次数:0 运行 AI代码解释 function isBigEnough(element,index,array) { return element >= 15; } console.log([12, 5, 8, 130, 44].findIndex(isBigEnough,this)); // 3 console.log([12, 5, 8, 130, 44]._findIndex(isBi...
The findIndex() method returns the index of the first element in an array that pass a test (provided as a function).The findIndex() method executes the function once for each element present in the array:If it finds an array element where the function returns a true value, findIndex()...
Given two array Idx_of_pt and P, I'd like to find all the row element in P from Idx_of_pt Idx_of_pt=[1 2 3;4 6 7;2 3 5]; P=[-0.03 0.12 0.04 -0.94 0.12 0.01 -0.06 0.15 0.037 -0.22 0.13 0.02 -0.26 0.12 0.07