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 string that you want to search. var string = 'Hello! 123! Test!'; //The sub...
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...
includes()Returns if a string contains a specified value 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
Pre-ES6, the common way to check if a string contains a substring was to use indexOf, which is a string method that return -1 if the string does not contain the substring. If the substring is found, it returns the index of the character that starts the string....
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...
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 ...
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...