The **`index` method** returns the index of the first occurrence of a substring in a string. If the substring is not present in the string, then the `ValueError: substring not found` exception is thrown.

# Syntax

```
string.index(substring [, start[, end]] )
```

# Arguments

* `substring`: The string to be searched. 

* `start`: The index from which the substring search should start. This is an optional value, and by default the value is `0`.

* `end`: The index to which the substring search should happen. This is an optional value, and by default the value is the length of the string.

# Return value

The return value is the first index at which the substring is found. If the substring is not present, an exception is thrown. 

# Example

string = "JavaScript";
print("The index of Java in JavaScript is")
print(string.index("Java"));

print("\nThe index of Script in JavaScript is")
print(string.index("Script"));


print("\nThe searching for 'pt' in JavaScript from index 8")
print(string.index("pt", 8));

print("\nThe searching for 'va' in JavaScript from index 1 and 5")
print(string.index("va", 1,5));


try:
  print("\nThe index of Python in JavaScript is")
  print(string.index("Python"));  
except ValueError as ve:
  print("Error", ve)


In the above code, we created a string, `JavaScript`:

```
string.index("Java")
```
* We used the `index` method to check the index at which `Java` is present in the `JavaScript` string. We will get `0` as result.
---

```
string.index("Script")
```

* We used the `index` method to check the index at which `Script` is present in the `JavaScript` string. We will get `4` as result.
---

```
string.index("pt", 8)
```

* We used the `index` method to check the index at which `pt` is present in the `JavaScript` string from the `8th` index. We will get `8` as result.

---

```
string.index("va", 1,5)
```
* We used the `index` method to check the index at which `va` is present in the `JavaScript` string between the 1 to 5 index. We will get `2` as result.
---
```
print(string.index("Python"));  
```

* We used the `index` method to check the index at which `Python` is present. We will get `ValueError` because `Python` is not present in the `JavaScript` string.

What is the string.index method in Python?

Syntax

Arguments

Return value

Example