function isString(value) {
return typeof value === 'string' || value instanceof String;
}
isString(''); // true
isString(1); // false
isString({}); // false
isString([]); // false
isString(new String('teste')) // true
//Here are the commonly used JavaScript String methods:
Method Description
charAt(index) returns the character at the specified index
concat() joins two or more strings
replace() replaces a string with another string
split() converts the string to an array of strings
substr(start, length) returns a part of a string
substring(start,end) returns a part of a string
slice(start, end) returns a part of a string
toLowerCase() returns the passed string in lower case
toUpperCase() returns the passed string in upper9 case
trim() removes whitespace from the strings
includes() searches for a string and returns a boolean value
search() searches for a string and returns a position of a matchcharAt()
charCodeAt()
concat()
endsWith()
includes()
indexOf()
lastIndexOf()
match()
matchAll()
repeat()
replace()
replaceAll()
search()
slice()
split()
startsWith()
substr()
substring()
toLowerCase()
toUpperCase()
toString()
trim()
valueOf()const text1 = 'hello';
const text2 = 'world';
const text3 = ' JavaScript ';
// concatenating two strings
const result1 = text1.concat(' ', text2);
console.log(result1); // "hello world"
// converting the text to uppercase
const result2 = text1.toUpperCase();
console.log(result2); // HELLO
// removing whitespace from the string
const result3 = text3.trim();
console.log(result3); // JavaScript
// converting the string to an array
const result4 = text1.split();
console.log(result4); // ["hello"]
// slicing the string
const result5= text1.slice(1, 3);
console.log(result5); // "el"const a = 225; // number
const b = true; // boolean
//converting to string
const result1 = String(a);
const result2 = String(b);
console.log(result1); // "225"
console.log(result2); // "true"