function rollCall(name, index, array) { let nextItem = index + 1 < array.length ? "postive" : "negative" console.log(`Is the number ${index + 1} student - ${name} present? Yes!. Is there a next student? ${nextItem}!`); } names.forEach((name, index, array) => rollCall(...
10、使用 indexOf() 检查元素是否存在 JavaScript 为我们提供了内置方法 indexOf()。 这个方法让我们可以方便地检查某个元素是否存在于数组中。 indexOf() 方法接受一个元素作为输入参数,并返回该元素在数组中的位置(索引);若该元素不存在于数组中则返回 -1。 function quickCheck(arr, elem) { return arr.index...
string-in-js npm package The string-in-js npm package provides string manipulation functions designed to enhance JavaScript's built-in string capabilities. It provides a set of intuitive functions that allow you to easily transform and manipulate strings in various ways. Installation To start using...
indexOf()Returns the index (position) of the first occurrence of a value in a string lastIndexOf()Returns the index (position) of the last occurrence of a value in a string lengthReturns the length of a string localeCompare()Compares two strings in the current locale ...
In JavaScript, indexOf() is a string method that is used to find the location of a substring in a string. Because the indexOf() method is a method of the String object, it must be invoked through a particular instance of the String class.Syntax...
String.prototype.lastIndexOf()从字符串对象中返回最后一个被发现的给定值的索引值,如果没有找到则返回-1。 String.prototype.localeCompare()返回一个数字表示是否引用字符串在排序中位于比较字符串的前面,后面,或者二者相同。 String.prototype.match()使用正则表达式与字符串相比较。 String.prototype.normalize()返回...
System.out.println("字符串的长度是:"+str.length()); //字符串的雪字打印输出 charAt(int index) 代码语言:txt AI代码解释 System.out.println(str.charAt(4)); //取出子串 天欲 代码语言:txt AI代码解释 System.out.println(str.substring(2)); //取出从index2开始直到最后的子串,包含2 ...
text.indexOf("a"); Try it Yourself » Description TheindexOf()method returns the position of the first occurrence of a value in a string. TheindexOf()method returns -1 if the value is not found. TheindexOf()method is case sensitive. ...
原型:stringObject.charCodeAt(index) 用法: varstr="Hello world!"console.log(str.charCodeAt(1)) 输出: 101 concat() 描述:用于连接两个或多个字符串。 原型:stringObject.concat(stringX,stringX,...,stringX) 用法: varstr1 ="Hello "varstr2 ="world...
根据前面的源代码var word = s.substring(s.indexOf(" ")+1,s.length);,现在要执行s.substring(),在V8执行逻辑中,先要获取字符串s的substring()方法,也就是’.’操作。前述字节码中第14、15行把刚定义的字节串s存到了r2寄存器中,代码16行:LdaNamedPropertyNoFeedback r2, [3]这条字节码的作用是在r2...