What is the `String.prototype.indexOf` method in JavaScript?
Description : `indexOf` returns the index of the first occurrence of a specified value in a string.
Answer :
`String.prototype.indexOf` returns the index of the first occurrence of a specified value in a string. If the value is not found, it returns -1.const str ='hello';const index = str.indexOf('l');
console.log(index);// 2
`Array.prototype.flat` creates a newarraywith all sub-array elements concatenated into it recursively up to a specified depth. It can flatten nested arrays to a specified level.const arr =[1,[2,[3,[4]]]];const flatArr = arr.flat(2);
console.log(flatArr);// [1, 2, 3, [4]]
`Array.prototype.flat` creates a newarraywith all sub-array elements concatenated into it recursively up to a specified depth. It can flatten nested arrays to a specified level.const arr =[1,[2,[3,[4]]]];const flatArr = arr.flat(2);
console.log(flatArr);// [1, 2, 3, [4]]
What is the `String.prototype.bold` method in JavaScript?
`String.prototype.bold` returns a string wrapped inHTML`<b>` tags. Note that this method is deprecated and should not be used in modern applications.const str ='hello';const boldStr = str.bold();
console.log(boldStr);// '<b>hello</b>'
`String.prototype.bold` returns a string wrapped inHTML`<b>` tags. Note that this method is deprecated and should not be used in modern applications.const str ='hello';const boldStr = str.bold();
console.log(boldStr);// '<b>hello</b>'