Which of the following function is used to find the first occurrence of a given string in another string?

To find the first occurrence of a given string within another string, you can use the indexOf function in many programming languages, such as JavaScript, Java, and PHP. In Python, the equivalent function is find().

Here’s a brief overview of how it works:

1. Syntax: The general syntax for indexOf is:

   • string.indexOf(substring)

   And for Python’s find():

   • string.find(substring)

2. Return value:

   • Both functions return the index of the first occurrence of the specified substring. If the substring is not found, indexOf returns -1, while find() returns -1 as well.

3. Example:

   • In JavaScript:

     let str = "Hello, world!";
     let position = str.indexOf("world");
     console.log(position); // Output: 7
     

Overall, these functions are quite handy for string manipulation tasks in programming.