Interview Questions- Part-20

Find number of properties in an object

				
					var student = {
  name: "Anurag Nayak",
  empId: "123",
  1: "test",
  nestedObj: {
    id: 123,
    nestedObj1: {
      nestedObj2: {
        nestedObj3: {
          nestedObj4: {},
        },
      },
    },
  },
  testFunc2: function () {
    console.log(2);
  },
  testFunc3: () => {
    console.log(3);
  },
};

//1.calculate property length -->6
Object.keys(student).length;

Find the depth of nestedObj inside the student array

				
					//2.Find the nested object depth :->nestedObj --> length
//Object.values(nestedObj).forEach((v) => will loop on values
//typeof v ==> to determine if its object or not
//v==>{nestedObj2: {…}} {nestedObj3: {…}} {nestedObj4: {…}}

var student = {
  name: "Anurag Nayak",
  empId: "123",
  1: "test",
  nestedObj: {
    id: 123,
    nestedObj1: {
      nestedObj2: {
        nestedObj3: {
          nestedObj4: {},
        },
      },
    },
  },
  testFunc2: function () {
    console.log(2);
  },
  testFunc3: () => {
    console.log(3);
  },
};


let depth = 0;
let depthOfNestedObject = (nestedObj) => {
  Object.values(nestedObj).forEach((v) => {
    if (typeof v === "object") {
      depth++;
      depthOfNestedObject(v);
    }
  });
};

depthOfNestedObject(student.nestedObj);
console.log(`%c ${depth}`, "color:red;font-size:20px");

//output :- 4

find all the functions in the same object 

				
					var student = {
  name: "Anurag Nayak",
  empId: "123",
  1: "test",
  nestedObj: {
    id: 123,
    nestedObj1: {
      nestedObj2: {
        nestedObj3: {
          nestedObj4: {},
        },
      },
    },
  },
  testFunc2: function () {
    console.log(2);
  },
  testFunc3: () => {
    console.log(3);
  },
};


Object.values(student).forEach((v) => {
  if (typeof v === "function") console.log(v);
});

comibinations of the string

				
					//input string -test
//output should be --> ['t','te','tes','test','e','es','est','s','st','t']


let combinations = (str) => {
  var final = [];
  for (var i = 0; i < str.length; i++) {
    for (var j = i + 1; j < str.length + 1; j++) {
      final.push(str.slice(i, j));
    }
  }
  return final;
};

console.log(combinations("test"));


/*Explanations
As you know in slice -->last index is exclusive and first index is inclusive
so it will exclude the last index ..
so for example 
"test".slice(0,1) ==>t 
0th index will be included -->t
1st index is excluded --> e is excluded ...


******ITERATIONS**
i=0,j=1 to 4
"test".slice(0,1) ==>t
"test".slice(0,2) ==>te
"test".slice(0,3) ==>tes
"test".slice(0,4) ==>test

i=1,j=2 to 4
"test".slice(1,2) ==>e
"test".slice(1,3) ==>es
"test".slice(1,4) ==>est

i=2,j=3 to 4
"test".slice(2,3) ==>s
"test".slice(2,4) ==>st

i=3,j=4 to 4
"test".slice(3,4) ==>t

*/

Extension method to captialize the first letter of string

				
					String.prototype.CapitalizeFirstLetter = function () {
  return this[0].toUpperCase() + this.substring(1);
};

console.log("test".CapitalizeFirstLetter());

//Output:- Test

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