To check if the first letter of a string is uppercase: Use theString.charAt()method to get the first letter of the string. Use theString.toUppercase()method to convert the letter to uppercase. Compare the result to the letter. index.js ...
Check if First Letter Is Upper Case in JavaScript We can check if the first of a letter a string is upper case in a few ways. Let's take a look at some popular ones. toUpperCase() This is a built-in string method that returns the invoked string with only upper case characters: func...
可以使用String作为toString()更可靠的代替方法,因为它在用于null和undefined时仍然有效。例如: js constnullVar=null;nullVar.toString();// TypeError: nullVar is nullString(nullVar);// "null"constundefinedVar=undefined;undefinedVar.toString();// TypeError: undefinedVar is undefinedString(undefinedVar);/...
In JavaScript, toUpperCase() is a string method that is used to convert a string to uppercase. Because the toUpperCase() method is a method of the String object, it must be invoked through a particular instance of the String class. Syntax In JavaScript, the syntax for the toUpperCase() me...
string-in-js provides the following functions for string manipulation: capitalizeString(string) Converts the first character of a string to uppercase. Example: const { capitalizeString } = require('string-in-js'); console.log(capitalizeString('hello')); // Output: Hello console.log(capitalize...
write("Original string is: ", original_str); const uppercase_str = original_str.toUpperCase(); document.write("New string(after converting into uppercase) is: ", uppercase_str); OutputThe above program returns "TUTORIALSPOINT" in the output −Original string is: tutorialspoint New strin...
const str = "Hello World"; const upperCase = str.toUpperCase(); // "HELLO WORLD" // toString():将一个数值转换为字符串。 const num = 42; const str = num.toString(); // "42" // valueOf():返回一个字符串对象的原始值。 const strObj = new String("Hello World"); const value =...
React Js Check First Letter of String is Uppercase:In React.js, you can check if the first letter of a string is uppercase using various methods. One way is to use the toUpperCase() method to convert the first letter to uppercase and then compare it with the original string. Another ...
js uppercase the first letter of string js String.toUpperCase `-webkit-border-image`.split(`-`).filter(i=>i !=="").reduce((acc, i) =>acc += i)// "webkitborderimage"`-webkit-border-image`.split(`-`).filter(i=>i !=="").reduce((acc, i) =>acc += i[0].toUpperCase() +...
Here, we will create a function calledisUpperCase(), an anonymous arrow function, to tell us whether all the characters in a string are in uppercase. If so, it prints a message in the console. If any of the characters in a string are not in the uppercase format, it will print them...