Math Functions

Math.round(x)-Returns x rounded to its nearest integer
Math.ceil(x) -Returns x rounded up to its nearest integer
Math.floor(x)-Returns x rounded down to its nearest integer
Math.trunc(x)-Returns the integer part of x (new in ES6)
Math.pow(x, y) returns the value of x to the power of y
Math.sqrt(x) returns the square root of x
Math.abs(x) returns the absolute (positive) value of x
Math.log(x) returns the natural logarithm of x
Math.log10(x) returns the base 10 logarithm of x

String Functions

charAt(indexOfCharacter) method: This method returns the character at the specified index. String in JavaScript has zero-based indexing. Parameters: This method accepts single parameter indexOfCharacter that holds the Index of the character of any string. Example: This example describes the JavaScipt string charAt() method.
charCodeAt(indexOfCharacter) Method: This method returns a number that represents the Unicode value of the character at the specified index. This method accepts one argument.
concat( objectOfString ) Method: This method combines the text of two strings and returns a new combined or joined string. To concatenate two strings, we use concat() method on one object of string and send another object of string as a parameter. This method accepts one argument. The variable contains text in double quotes or single quotes.
indexOf(queryString) Method: This method returns the index of first occurrence of given query string. This method returns -1, if given character or string is not present in string variable. This method is case-sensitive. This method accepts single parameter queryString that holds the Character or string for getting index of that string.
replace(replaceValue, replaceWithValue) Method: This method returns string with the changes. This method is case-sensitive.
slice(startIndex, endIndex) Method: This method extract a part of string and returns a new string.
split(character) Method: This method splits the string into an array of sub-strings. This method returns an array. This method accepts single parameter character on which you want to split the string.
startsWith(queryString) Method: This method checks if a string starts with a given query string or not. This method returns “true” if string starts with provided query string else it returns “false”. This method accepts single parameter queryString that you want to check existing string start with it or not.