YOUR MISSION
Google maps recently discovered a mysterious place last week...
They need you to calculate new data on this unknown archipel...
Do you feel ready to continue this adventure?
INSTRUCTIONS :
Return the truncated percentage of islands on the map.
EXEMPLES
[
[0,0,0,0,0],
[1,1,0,0,0],
[1,1,0,0,0],
[0,0,0,1,1],
]
=>30%
const map=[
[0,0,0,0,0],
[1,1,0,0,0],
[1,1,0,0,0],
[0,0,0,1,1],
];
function count Islands(map){
return map.reduce((count Island,row)=>{
return count Island+row.filter(Boolean).length
},0);
}There are several steps:
1. Learn Javascript
2. Solve some questions
3. Read Javascript code
4. Start making some simple questions
5. Get someone's feedback
6. Improve the quality of questions
7... Do it again and againInside which HTML element do we put the JavaScript?
1. <script>
2.<js>
3.scriptinf>
4.<javaScript>
answer : <script>
<!-------------------------------------------------->
- What is the correct JavaScript syntax to change the content of the HTML element below?
<p id="demo">This is a demonstration.</p>
1. document.detElementById("demo").innerHTML="Hello Mohammad"
2. document.detElementBy("demo").innerHTML="Hello Mohammad"
3. detElementById("demo").innerHTML="Hello Mohammad"
4. document.detElementById("demo")="Hello Mohammad"
answer : 1. document.detElementById("demo").innerHTML="Hello Mohammad"
<!-------------------------------------------------->
-Where is the correct place to insert a JavaScript?
1. in the <body>
2. in the <head>
3. in both <head> and <body>
answer: 3. in both <head> and <body>
<!-------------------------------------------------->
-What is the correct syntax for referring to an external script called "xxx.js"?
1.<script src="xxx.js">
2.<script name="xxx.js">
3.<script href="xxx.js">
answer : 1.<script src="xxx.js">
<!-------------------------------------------------->
-The external JavaScript file must contain the <script> tag.
1.true
2.false
answer: 2.false
<!-------------------------------------------------->
Below are some helpful JS questions and awnsers to test you JS skills:
Q1) - Which of the following is an advantage of using JavaScript?
A - Less server interaction
B - Immediate feedback to the visitors
C - Increased interactivity
D - All of the above.
(ANSWER) - D
Q2) - Can you assign a anonymous function to a variable?
A - true
B - false
(ANSWER) - A
Q3) - Which of the following type of variable takes precedence over
other if names are same?
A - global variable
B - local variable
C - Both of the above.
D - None of the above.
(ANSWER) - B
Q4) - Which built-in method reverses the order of the elements of
an array?
A - changeOrder(order)
B - reverse()
C - sort(order)
D - None of the above.
(ANSWER) - B
Q5) - Which of the following function of Array object applies a function
simultaneously against two values of the array (from right-to-left) as to
reduce it to a single value?
A - pop()
B - push()
C - reduce()
D - reduceRight()
(ANSWER) - D