String Methods

const firstName = 'William';
const lastName = 'Johnson';
const tags = 'web design,web development,programming';

length (property; no paranthesis)

console.log(firstName.length); //yields 7

 

concat(<str value>, <str value2>, ...)

console.log(firstName.concat(' Smith')); // yields "William Smith"

 

toUpperCase(<str value>), toLowerCase(<str value>)

console.log(firstName.toUpperCase()); //yields "WILLIAM"
console.log(firstName.toLowerCase()); //yields "william"

 

indexOf(<str value>)

- returns the start index of the str value

console.log(firstName.indexOf('l')); //yields 2

 

charAt(<number with str value>)

- returns the char in that index

console.log(firstName.charAt(0)); //yields "w"

 

substring(<index>, <index>)

console.log(firstName.substring(0, 4)); //yields "will"

 

slice(<index>, ...)

- we can use the negative index which counts from backward

console.log(firstName.slice(0, 4)); //yields "will"
console.log(firstName.slice(-3)); //yields "iam"

 

split(<str value>)

- split strings in arrays with provided str value

console.log(tags.split(',')); //yields ["web design", "web development", "programming"]

 

replace(<str value>, <str value>)

console.log(firstName.replace("will", "James")); //yields "Jamesiam"

 

includes(<str value>)

- returns true if str value is included in the string or false otherwise

console.log(tags.includes("web development"); //yields true
console.log(tags.includes("foo")); //yields false