We cannot directly use contains in javascript. We need to use indexOf() as an alternate to contains in javascript
Example:
var str = "Hello world, welcome to the universe.";
var res = str.indexOf("world");
If the given string is present ,then indexOf() will return index of that string.
So, the above code gives 6 as output(6 is index of string 'world')
other Example:
var str = "Hello world, welcome to the universe.";
var res = str.indexOf("King");
The above code gives -1 as output as 'king' is not present in input string "str".
So,as an alternate to conatins() we need to use indexOf() like this
if(str.indexOf("world") != -1) {
if string matches,it comes into this block
} else {
if string doesn't match,it will come to this block
}
Note: Test the below piece of code by coping it into the following Editor.
<!DOCTYPE html>
<html>
<body>
<p>Click the button to locate the first occurance of the letter .</p>
<button onclick="myFunction()">Try it</button>
<p id="demo"></p>
<script>
function myFunction() {
var str = "Hello world, welcome to the universe.";
var res = str.indexOf("world");
document.getElementById("demo").innerHTML = res;
}
</script>
</body>
</html>
Example:
var str = "Hello world, welcome to the universe.";
var res = str.indexOf("world");
If the given string is present ,then indexOf() will return index of that string.
So, the above code gives 6 as output(6 is index of string 'world')
other Example:
var str = "Hello world, welcome to the universe.";
var res = str.indexOf("King");
The above code gives -1 as output as 'king' is not present in input string "str".
So,as an alternate to conatins() we need to use indexOf() like this
if(str.indexOf("world") != -1) {
if string matches,it comes into this block
} else {
if string doesn't match,it will come to this block
}
Note: Test the below piece of code by coping it into the following Editor.
<!DOCTYPE html>
<html>
<body>
<p>Click the button to locate the first occurance of the letter .</p>
<button onclick="myFunction()">Try it</button>
<p id="demo"></p>
<script>
function myFunction() {
var str = "Hello world, welcome to the universe.";
var res = str.indexOf("world");
document.getElementById("demo").innerHTML = res;
}
</script>
</body>
</html>
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