javascript if (index !== -1) { console.log("The index of '" + searchString + "' is: " + index); } else { console.log("'" + searchString + "' was not found in the string."); } 完整示例代码 javascript const exampleSt
问如何在javascript中使用"indexOf“ENindexOf()是js中内置的方法之一，它的功能大家都很熟悉：简单来说...
Javascript contains -检查多个值 javascript condition contains for conditionalpanel in shiny 为什么contains (值)包含值时等于false? javascript变量等于iframe Javascript -数组之和等于NaN Javascript -子集总和等于K 当在ArrayList中找到字符串时,ArrayList.contains()等于false ...
// index is -1 Example: Finding all the occurrences of an element The following example usesindexOfto find all the indices of an element in a given array, usingpushto add them to another array as they are found. varindices = []; varidx = array.indexOf(element); while(idx != -1)...
In JavaScript, `indexOf()` is a method commonly used to find the first occurrence of a specified value in a string or an array, and returns its position. If the value is not found, it returns -1. 在JavaScript中,`indexOf()`是一个常用于在字符串或数组中查找指定值的首次出现位置的方法,...
let email = 'user3@example.com'; if (users.indexOf(email) === -1) { console.log('Email is available'); } else { console.log('Email is already taken'); } 1.2、动态列表操作 在Vue项目中,常需要对动态列表进行操作,比如删除或更新某个元素。通过indexOf找到元素位置后,可以轻松地进行这些操作...
var myArray = []; myArray.push(hello,qaz); Now I would like to have theindexOfthe object whichhelloproperty is'stevie'which, in this example, would be1. 我是JavaScript 的新手,我不知道是否有简单的方法,或者我是否应该构建自己的函数来做到这一点。
Here, we have passed"Python"as asubstr. Since"Python"is not found in the"I love JavaScript"string, the method returns-1. Example 4: lastIndexOf() For Case-Sensitive Search ThelastIndexOf()method is case sensitive. For example: varstr ="I love JavaScript"; ...
Example constmessage ="JavaScript is not Java"; // returns index of 'v' in first occurrence of 'va'constindex = message.indexOf("va"); console.log('index: '+ index);// index: 2 indexOf() Syntax The syntax of theindexOf()method is: ...
However, we would receive a -1 if it doesn’t occur in the searched string. Using the JavaScript indexOf method on strings Let’s consider an example where we use this method to get the index of the first occurrence of the substring “flexiple.” Input: let devs = 'Join as a ...