Get the index of the first element in the array that has a value above a specific number: <p>Minimum age: <input type="number" id="ageToCheck" value="18"></p> <button onclick="myFunction()">Try it</button><p>Any
letlanguages = ["Java","JavaScript","Python","JavaScript"];// get the index of the first occurrence of "JavaScript"letindex = languages.indexOf("JavaScript");console.log(index);// Output: 1 indexOf() 语法 用法: arr.indexOf(searchElement,fromIndex) 这里,arr是一个数组。 参数: indexOf()...
first: element inserted at the beginning of array last: element inserted at the end of array. 代码语言:javascript 代码运行次数:0 运行 AI代码解释 functionappend(array,toAppend){constarrayCopy=array.slice();if(toAppend.first){arrayCopy.unshift(toAppend.first);}if(toAppend.last){arrayCopy.push(...
两个位置方法:indexOf()和lastIndexOf(),这两个方法都接收两个参数:要查找的项和(可选的)表示查找七点位置的索引. 1)indexOf():从数组的开头(位置0)开始向后查找 2)lastIndexOf():从数组的末尾开始向前查找 这两个方法都返回查找的项在数组中的位置,或者在没找到的情况下返回-1. 在比较第一个参数与数...
indexOf() includes() find() indexOf() 返回要查找的元素在数组中的位置,如果没找到则返回 -1 我们首先创建了一个数组array。然后,我们使用indexOf()方法来查找数字3在数组中的位置,结果为2(索引从0开始)。接着,我们使用indexOf()方法查找数字6在数组中的位置,由于数组中没有数字6,所以返回-1。 需要注意...
Here is how to retrieve the index of an item in a JS array based on its valueTHE SOLOPRENEUR MASTERCLASS Launching June 24th Suppose you have the value of an item which is contained in an array, and you want to get its index.
)//0-n array: [0, 1, 2, 3, 4, 5, 6, 7, 8, 9] 三、类型检测和原型 1、类型检测 现在检测数组都是用 Array.isArray(ES5 新增),对于以前的检测方法也要了解。 在ES5 以前,Array 的检测并没有一个统一的标准,一般使用的方法有: let arr5 =[]//instanceofconsole.log('instanceof', arr5in...
To get an index of the maximum value in a JavaScript array: Initialize maximum value with first element of the array. Iterate over the array using for loop. In each iteration, compare if current element is greater than maximum value. If yes, update the maximum value and its index. Once ...
// get the index of the first occurrence of "JavaScript"letindex = languages.indexOf("JavaScript"); console.log(index);// Output: 1 indexOf() Syntax The syntax of theindexOf()method is: arr.indexOf(searchElement, fromIndex) Here,arris an array. ...
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']; ...