FOLLOW US
In this section, we shall look at some of the
operations that could be performed with strings or on string. We will also look
at some string methods.
Concatenating Strings
To concatenate strings, mean to join two
(2) strings together to form a single sign, basically this can be done using a plus (+) operator.
Example:
var f_name = 'Joy'
var l_name = 'Lawson''
var full_name = f_name +" "
+ l_name
Output:
// Joy Lawson
Comparing
strings
In JavaScript, you just use the less-than
and greater-than operators:
var a = 'a';
var b = 'b';
if (a < b) {
console.log(a + ' is less
than ' + b);
} else if (a > b) {
console.log(a + ' is
greater than ' + b);
} else {
console.log(a + ' and
' + b + ' are equal.');
}
output:
// a is less than b
Converting/Casting strings
By using String() or toString() functions,
you can change the value of a string to an object or change the value of a data
type to a string data type.
var d_string= 'foo';
var d_str_obj = new String (d_string);
console.log (typeof d_string);
Output:
// creates a string primitive "string"
Output:
console.log (typeof d_str_obj);
// creates a String object "object"
Similarly, Other data types or objects, can
be converted to string, using the same String or toString keywords.
function about_Strings() {
var val_1 = new Date();//
date object
var val_2 = "2700"; //string
var val_3 = 2700 // number;
var new_str_val = String(val_1) + "<br>" +
toString(val_2) + "<br>" + toString(val_3);
document.getElementById("demo").innerHTML
= res;
}
Output:
Sat Jan 26 2019 03:00:54 GMT+0000 (Greenwich
Mean Time)
12345
12345
Manipulating Strings
There are so many effect we can
achieve by manipulating a given string or strings In this Example, we
are going to be using three string methods:
split();
reverse();
join();
function myFunction() {
var dDtring2= 'Programming is interesting'
let splitted=
dDtring2.split('').reverse().join('-');
document.getElementById("demo").innerHTML = splitted;
}
Output:
g-n-i-t-s-e-r-e-t-n-i- -s-i-
-g-n-i-m-m-a-r-g-o-r-P
Aside from these methods mentioned here, there
are many others including:
charAt(), charCodeAt(), concat(), endsWith(), includes(), indexOf(), lastIndexOf(), match(), repeat(), replace(), search() slice(), split(), startsWith(), substr(), substring(), toLocaleLowerCase(), toLowerCase(), toString(), toUpperCase(), trim(), valueOf().
Meanwhile, you can give the examples we
have used above a try, to see how they work
Example: Working With Strings
<html>
<head>
</head>
<body>
<img id="source_image" alt=".." src = 'C:\Users\Grace\Desktop\LUVPIX.JPG' /><br>
<h1>WORKING WITH STRINGS</h1> <br>
Enter any text: <input id="myInput"
type="text">
How many letter are you expecting?: <input
id = "myInput2" type="text">
<input id="btn" type="button" value =
'Randomnise' onclick='word()'/><br>
<p id="demo"></p>
<script>
function word(){
var starting_String = "";
var get_value =
document.getElementById("myInput").value;
var get_value2 =
document.getElementById("myInput2").value;
var int_get_value2 = parseInt(get_value2,
10)
var start_name=function(){
return
}
if (get_value.length > int_get_value2){
while
(starting_String.length <int_get_value2 ) {
starting_String = starting_String + get_value[Math.floor(Math.random() *
get_value.length)];
}
document.getElementById("demo").innerHTML=starting_String;
}
else {
document.getElementById("demo").innerHTML='Please enter a text
longer than' +' ' + int_get_value2;
}
}
</script>
</body>
</html>
