toUpperCase()method does not affect the original string, returning a new modified string instead.
toUpperCase() function won't be modified. Instead, the method generates a new string with all letters properly capitalized.
var str = "Hi, Mark!"; var res = str.toUpperCase();
uppercaseFirstLetter to strings.
Tip: toLowerCase() method can be used for converting the string to lowercase letters.
Theory is great, but we recommend digging deeper!
Learn Standard Syntax
You should notice that parentheses are empty, meaning that it does not take any arguments.
|Return Value:||A string, which represents the original string with the letters all converted to uppercase.|