Therefore, if the return value is not -1, we can safely assume that the string does contain the substring we are looking for. Note that you can also use this method to search for a single character. Why not use the includes() method? You can also use theString.prototype.includes()meth...
DOCTYPEhtml><html><head><meta charset="UTF-8"><title></title></head><body><script>//js对象varuser={name:"张学友",address:"中国香港"};console.log(typeof(user));console.log(typeof(null));console.log(typeof(undefined));console.log(user.name);console.log(user.age);if(user.age){con...
if (str.slice(searchFromIndex).includes(searchValue)) { console.log(`${searchValue} is found after index ${searchFromIndex}.`); } 3. 组合使用其他字符串方法:与其他字符串方法(如trim(),split(),substring(),replace()等)配合,可以实现更复杂的文本处理逻辑。 const sentence = "A quick brown fox...
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...
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....
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(...
constructorReturns the string's constructor function endsWith()Returns if a string ends with a specified value fromCharCode()Returns Unicode values as characters includes()Returns if a string contains a specified value indexOf()Returns the index (position) of the first occurrence of a value in a...
functiongetMatchesCountString(results) {if(results.length===1) {return"<p>There was one match.</p>"; }else{return"<p>There are "+ results.length+" matches.</p>"; } } 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: ...
Here, since our first-string variablestr_1contains all the uppercase valuesAB% ^M. Therefore, it has printed all the characters are in uppercase. Note that there is a space character inside this string as well. Inside the second string variablestr_2, from all the charactersIO(|12c, we ...
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...