Array of Object

15 |

16 |

 17 |                 let studentRecords = [ {name: 'John', id: 123, marks : 98 },
 18 |                 {name: 'Baba', id: 101, marks : 23 },
 19 |                 {name: 'yaga', id: 200, marks : 45 },
 20 |                 {name: 'Wick', id: 115, marks : 75 } ]
 21 |

22 |

23 |

24 |

25 |

Q1 :- We are interested in retrieving only the students' names; all the names should be in caps.
26 | ['JOHN', 'BABA', 'YAGA', 'WICK']

27 |

ANS:-

28 |

 29 |                 studentRecords.map((item)=>{
 30 |                     console.log(item.name.toUpperCase())
 31 |                 })
 32 |

33 |

ANS :- ['JOHN', 'BABA', 'YAGA', 'WICK']

34 |

35 |

36 |

37 |

Q2 :- Suppose we have the same dataset as above but this time we want to get the details of students who scored more than 50 marks.
38 | [{name: 'John', id: 123, marks: 98 },{name: 'Wick', id: 115, marks: 75 }] 39 |

40 |

ANS :-

41 |

 42 |                 studentRecords.map((item)=>{
 43 |                     if(item.marks > 50){
 44 |                         console.log(item)
 45 |                     }
 46 |                 })
 47 |

48 |

OUTPUT :- {name: 'John', id: 123, marks: 98}
49 | {name: 'Wick', id: 115, marks: 75} 50 |

51 |

52 |

53 |

54 |

Q3 :- Retrieve the details of students who scored more than 50 marks and have IDs greater than 120.

55 |

ANS :-

56 |

 57 |                 studentRecords.map((item) => {
 58 |                     if (item.marks > 50 && item.id > 120) {
 59 |                       console.log(item);
 60 |                     }
 61 |                   });
 62 |

63 |

OUTPUT :- { name: 'John', id: 123, marks: 98 }

64 |

65 |

66 |

67 |

Q4 :- Consider the same scenario we have discussed above, but this time we would like to know the sum total of the marks of the students.

68 |

ANS :-

69 |

 70 |                 const sum = studentRecords.reduce((total, current) => {
 71 |                     return total + current.marks;
 72 |                     
 73 |                 }, 0);
 74 |                   console.log(sum);
 75 |

76 |

OUTPUT :- 241

77 |

78 |

79 |

80 |

Q5 :- This time we want to get only the names of the students who scored more than 50 marks from the same dataset used above.

81 |

ANS :-

82 |

 83 |                 studentRecords.map((item) => {
 84 |                     if (item.marks > 50) {
 85 |                       console.log(item.name);
 86 |                     }
 87 |                   });
 88 |

89 |

OUTPUT :- John
Wick

90 |

91 |

92 |

93 |

Q6 :- This time we are required to print the sum of marks of the students with id > 120.

94 |

ANS :-

95 |

 96 |                 const sum2 = studentRecords.filter((item) => {
 97 |                     return item.id > 120;
 98 |                 }).reduce((total, current) => {
 99 |                     return total + current.marks;
100 |                 }, 0);
101 |                 console.log(sum2);
102 |

103 |

OUTPUT :- 143

104 |

105 |

106 |

107 |

Q7 :- This time we are required to print the total marks of the students with marks greater than 50 after a grace of 15 marks has been added to those students who scored less than 50.

108 |

ANS :-

109 |

110 |                 function calculateTotalMarksWithGrace(student) {
111 |                     if (student.marks < 50) {
112 |                       // Add 15 grace marks if the student's marks are less than 50
113 |                       return student.marks + 15;
114 |                     } else {
115 |                       return student.marks;
116 |                     }
117 |                   }
118 |                   
119 |                   // Calculate and print total marks for students with marks greater than 50 after applying grace
120 |                   for (let i = 0; i < studentRecords.length; i++) {
121 |                     let student = studentRecords[i];
122 |                     let totalMarks = calculateTotalMarksWithGrace(student);
123 |                   
124 |                     if (totalMarks > 50) {
125 |                       console.log(`Student: ${student.name}, Total Marks: ${totalMarks}`);
126 |                     }
127 |                   }
128 |

129 |

OUTPUT :-
130 | Student: John, Total Marks: 98
131 | Student: yaga, Total Marks: 60
132 | Student: Wick, Total Marks: 75 133 |

134 |

135 |

136 |

137 |

Q8 :- Create 6 objects , each object will have name, class, roll no as properties. Store these objects in an array of objects.

138 |

ANS :-

139 |

140 |                 let student = [
141 |                 { name: 'John', class: '10th', rollNo: 1 },
142 |                 { name: 'Jane', class: '9th', rollNo: 2 },
143 |                 { name: 'Alice', class: '12th', rollNo: 3 },
144 |                 { name: 'Bob', class: '11th', rollNo: 4 },
145 |                 { name: 'Sarah', class: '8th', rollNo: 5 },
146 |                 { name: 'Mike', class: '10th', rollNo: 6 }
147 |                 ];
148 |                 console.log(student);
149 |

150 |

151 |

152 |

Array of Object - Handson