步骤2: 从后往前查找子字符串 我们使用 JavaScript 提供的lastIndexOf方法,它可以从后往前查找子字符串的位置。代码如下: // 从后往前查找子字符串constindex=targetString.lastIndexOf(searchString);// 输出查找到的索引console.log(`The last occurrence of '${searchString}' is at index:${index}`); 1....
// find last occurrence of "m" in strvarresult = str.lastIndexOf(substr); console.log(result); Run Code Output 7 In the above example, we have defined a string namedstr. Thesubstrvariable contains"m"which is a substring of the given string. ThelastIndexOf()method locates the index of...
Finding a String Inside Another StringYou can use the indexOf() method to find a substring or string within another string. This method returns the index or position of the first occurrence of a specified string within a string.ExampleTry this code » let str = "If the facts don't fit...
_.findIndex 的作用就是从一个数组中找到第一个满足某个条件的元素,_.findLastIndex 则是找到最后一个(或者说倒序查找)。 举个简单的例子: var arr = [ 1, 3, 5, 2, 4, 6]; var isEven = function(num) { return !(num & 1); }; var idx = _.findIndex(arr, isEven); // => 3 直接...
The lastIndexOf() method returns the position of the first occurrence of substring in string when searching the string backwards. The first position in the string is 0. If the lastIndexOf() method does not find the substring in string, it will return -1.Note...
For example, by default, regular expressions match only the first occurrence of the pattern in a search string. Also, matching is case-sensitive, which is maybe not what we want when searching for substrings. Because of that, we'll introduce two flags we'll be using for the purpose of ...
Find the position of the first occurrence of a text in a string - indexOf() Search for a text in a string and return the text if found - match() Replace characters in a string - replace() Convert string to upper case - toUpperCase() ...
stringif(typeofstr!=='string'){// Return a message if the input is not a stringreturn'It must be a string.'}// Create a Map to store the occurrences of each character in the stringconstoccurrence_Map=newMap()// Iterate through each character in the stringfor(constcharofstr){// ...
对恶意样本进行反混淆处理可能是一项比较繁琐的任务。为了减少这项任务所花费的时间,研究人员们正不断尝试进行自动化的反混淆处理。在本文中,我们将首先分析脚本中的四种不同混淆类型,并探讨如何在正则表达式的帮助下对其进行反混淆。在这里,我们将逐步分析反混淆过程,并尝试设计对应的反混淆工具。在成功进行了所有的反...
String.prototype.replaceAll = function (find, replace) { var str = this; return str.replace(new RegExp(find, 'g'), replace); }; Run Code Online (Sandbox Code Playgroud) 编辑 如果您find将包含特殊字符,那么您需要转义它们: String.prototype.replaceAll = function (find, replace) { var str...