forked from Prakshalshah78/DSA_Relevel
-
Notifications
You must be signed in to change notification settings - Fork 0
/
06_06.js
209 lines (143 loc) · 2.8 KB
/
06_06.js
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
//check if it is my array or not
const arr = [1,2,3,4]
//console.log(Array.isArray(arr))
//Javascript obj
const obj = {
a:10,
b:20
}
const myJson = JSON.stringify(obj);
console.log(myJson)
const arrNames = [1,2,3,4]
const myJsonArray = JSON.stringify(arrNames)
console.log(typeof myJsonArray)
//Fill
const arr=[1,2,3,4]
arr.fill("abc",2,4)
console.log(arr)
const age=[10,20,30,40,50,60,70]
//0 1 2 3
//find age > 20
//[30,40,50,60,70]
//1. Using filter method
const filteredAge =age.filter((elem)=>elem>20)
console.log(filteredAge)
//2. Using find method
const findAge = age.find(element=>element>20)
console.log(findAge)
//2d Arrays
const age=[
[1,2,4,5,6],
[2,3,4,5,44],
[29,39,48,18,24],
[84,23,212,23,45]
]
for(rows=0;rows<age.length;rows++){
for(cols=0;cols<age[rows].length;cols++){
console.log(age[rows][cols])
}
}
//iterative statements
/*
for
while
do-while
foreach
for in
for of
if
else
switch
break;
continue;
const arr = ["Apple","Rose","Summer"]
const obj = {
"fruit":"Apple",
"flower":"Rose",
"season":"Summer"
}
//for - in => indices will be fetched
//=> if you need to get the element then you need to do operation in array e.g arr[idx]
for(let idx in arr){
console.log(idx,arr[idx])
}
//for - of => entire element will be extracted
for(let elem of arr){
console.log(elem)
}
const arr = ["Apple","Rose","Summer"]
const obj = {
"fruit":"Apple",
"flower":"Rose",
"season":"Summer"
}
//console.log(Object.keys(obj))
//for - of
for(var key of Object.keys(obj)){
//console.log(obj[key])
}
//for - in
for(var key in obj){
console.log(obj[key])
}
*/
console.log(a)
var a=10;
//browser code
/*
var a;
console.log(a)
a=10;
*/
//=========let and const=========
console.log(aWithLet)
let aWithLet = 10;
//browser code
/*console.log(aWithLet);
let aWithLet;
aWithLet=10;*/
//by default only var is hoisted
//let and const does not support hoisting
/*let foo = "outer";
function x()
{
console.log("...");
let foo = "inner";
console.log(foo);
}
x();
*/
var foo = "outer";
function x()
{
console.log("...");
var foo = "inner";
console.log(foo);
}
x();
// Map - transforming an array
var origArr=[10,20,30,40]
//multiply every elem with 5
let mapArray = origArr.map((elem)=>elem*5)
console.log("origArr",origArr)
console.log("mapArray",mapArray)
// Filter - use to filter out the records as per demand / condition
const filtArr =origArr.filter((elem)=>elem>15)
console.log("filtArr",filtArr)
//[20,30,40]
//Reduce - return one value as output
const reduceArr= origArr.reduce((mul,elem)=>{
return mul*=elem
},1)
console.log(reduceArr)
// mul = mul*arr[i]
//pass by value and reference
//pass by value
function square(x) {
x = x * x;
return x;
}
let y = 10;
let result = square(y);
console.log(result); //
console.log(y); //