This is a JavaScript tutorial on how to check if a string contains a substring or character. To accomplish this, we will use theString.prototype.indexOf()method. Take a look at the following example: //The strin
log(cleanedData); // "UnsafeCharactersInHere" 实战技巧 1. 不区分大小写查找:虽然 includes() 默认区分大小写,但可以通过将字符串和查找值转换为统一的大小写形式(通常为全小写或全大写)来实现不区分大小写的查找。 const str = "Hello, World!"; const searchValue = "world"; if (str.toLowerCase(...
2. 内容过滤:在处理文本内容时,检测是否包含敏感词、非法字符或特定关键词,以进行内容审核、自动标记或过滤。 function containsProfanity(text) { const profanities = ["swearword1", "swearword2", "etc."]; return profanities.some(word => text.includes(word)); } const message = "This message contai...
它将打印:// DOMException: Failed to execute 'btoa' on 'Window': The string to be encoded contains characters outside of the Latin1 range.try { const validUTF16StringEncoded = btoa(validUTF16String); console.log(`Encoded string: [${validUTF16StringEncoded}]`); } catch (error) { console...
string – 如果变量是 String 类型的 object – 如果变量是一种引用类型或 Null 类型的 3)通过instanceof 运算符解决引用类型判断问题 4)null 被认为是对象的占位符,typeof运算符对于null值返回“object”。 5)原始数据类型和引用数据类型变量在内存中的存放如下: ...
If no character is found, [ ] returns undefined, while charAt() returns an empty string. It is read only. str[0] = "A" gives no error (but does not work!) Example lettext ="HELLO WORLD"; text[0] ="A";// Gives no error, but does not work ...
But instead of looping over the string, we’ll usetheString.prototype.split()methodto convert the string to an array. Then, we’ll usetheArray.prototype.filter()methodto create a new array of only unique characters. If the first matching character in the array has the sameindexas the curr...
In JavaScript, there is no built-in function to check if every character in a given string is in uppercase format or not. So, we have to implement our function. Here, we will create a function calledisUpperCase(), an anonymous arrow function, to tell us whether all the characters in a...
functiongetMatchesCountString(results) {if(results.length===1) {return"There was one match."; }else{return"There are "+ results.length+" matches."; } } 最后,我们有一个function,它将循环遍历results数组并创建一个 HTML 字符串以在页面上显示: functiongetResultsString...
contains(value),返回布尔值,表示给定的 value 是否存在。 remove(value),从类名列表中删除指定的字符串值 value。 toggle(value),如果类名列表中已经存在指定的 value,则删除;如果不存在,则添加。 # 焦点管理 HTML5 增加了辅助 DOM 焦点管理的功能。首先是 document.activeElement,始终包含当前拥有焦点的 DOM 元素...