Java String indexOf() Method
Example
Search a string for the first occurrence of "planet":
public class MyClass {
public static void main(String[] args) {
String myStr = "Hello planet earth, you are a great planet.";
System.out.println(myStr.indexOf("planet"));
}
}
Definition and Usage
The indexOf() method returns the position of the first occurrence of specified character(s) in a string.
Tip: Use the lastIndexOf method to return the position of the last occurrence of specified character(s) in a string.
Syntax
There are 4 indexOf() methods:
public int indexOf(String str)
public int indexOf(String str, int fromIndex)
public int indexOf(int char)
public int indexOf(int char, int fromIndex)
Parameter Values
| Parameter | Description |
|---|---|
| str | A String value, representing the string
to search for |
| fromIndex | An int value, representing the index position to start the search from |
| char | An int value, representing a single
character, e.g 'A', or a Unicode value |
Technical Details
| Returns: | An int value, representing the index of the first occurrence of the
character in the string, or -1 if it never occurs |
|---|
More Examples
Example
Find the first occurrence of the letter "e" in a string, starting the search at position 5:
public class MyClass {
public static void main(String[] args) {
String myStr = "Hello planet earth, you are a great planet.";
System.out.println(myStr.indexOf("e", 5));
}
}
❮ String Methods
