Most useful Javascript User-define function
1.Math.round()
<!DOCTYPE html>
<html>
<body>
<h2>JavaScript Math.ceil()</h2>
<p>Math.round() rounds a number <strong>up</strong> to its nearest integer:</p>
<p id=”math”></p>
<script>
document.getElementById(“math”).innerHTML = Math.round(99.99);
</script>
</body>
</html>
Output:-
JavaScript Math.round()
Math.round() rounds a number up to its nearest integer:
100
2. Math.floor()
<!DOCTYPE html>
<html>
<body>
<h2>JavaScript Math.floor()</h2>
<p>Math.floor(x) returns the value of x rounded <strong>down</strong> to its nearest integer:</p>
<p id=”math”></p>
<script>
document.getElementById(“math”).innerHTML = Math.floor(9.9);
</script>
</body>
</html>
Output:-
JavaScript Math.floor()
Math.floor(x) returns the value of x rounded down to its nearest integer:
9
3.Math.sign()
<!DOCTYPE html>
<html>
<body>
<h2>JavaScript Math.sign()</h2>
<p>Math.sign(x) returns if x is negative, null or positive:</p>
<p id=”math”></p>
<script>
document.getElementById(“math”).innerHTML = Math.sign(8);
</script>
</body>
</html>
Output: -
JavaScript Math.sign()
Math.sign(x) returns if x is negative, null or positive:
1
3.Math.random()
<!DOCTYPE html>
<html>
<body>
<h2>JavaScript Math.random()</h2>
<p>Math.random() returns a random number between 0 (included) and 1 (excluded):</p>
<p id=”math”></p>
<script>
document.getElementById(“math”).innerHTML = Math.random();
</script>
</body>
</html>
Output:-
JavaScript Math.random()
Math.random() returns a random number between 0 (included) and 1 (excluded):
0.6157665775209555
4. Finding a String in a String
var str = “Please locate where ‘locate’ occurs!”;
var pos = str.indexOf(“locate”);
Output
7
5. Searching for a String in a String
var str = “Please locate where ‘locate’ occurs!”;
var pos = str.search(“locate”);
Output
7
6. The slice() Method
var str = “Apple, Banana, Kiwi”;
var res = str.slice(-12, -6);
Output
Banana
7. Replacing String Content
str = “Please visit Microsoft!”;
var n = str.replace(“Microsoft”, “W3Schools”);
Output
Please visit w3School
8. Converting to Upper
var text1 = “Hello World!”;
var text2 = text1.toUpperCase();
Output
HELLO WORLD!
9.Converting to Lower Case
var text1 = “Hello World!”;
var text2 = text1.toLowerCase();
Output
hello world!
10. String.trim()
This function help to remove to the array.
var str = “ Hello World! “;
alert(str.trim());
Output
Hello World!