Java - String String Searching

Introduction

You can get the index of a character or a string within another string using the indexOf() and lastIndexOf() methods.

For example,

String str = new String("Apple");

int index;
index = str.indexOf('p');      // index will have a value of 1
index = str.indexOf("pl");     // index will have a value of 2
index = str.lastIndexOf('p');  // index will have a value of 2
index = str.lastIndexOf("pl"); // index will have a value of 2
index = str.indexOf("k");      // index will have a value of -1

indexOf() method starts searching from the start of the string and returns the index of the first match.

lastIndexOf() method searches from the end and returns the index of the first match.

If the character or string is not found in the string, these methods return -1.

Demo

public class Main {
  public static void main(String[] args) {
    String str = new String("Apple");

    int index;/* ww w  . ja  v  a  2  s  .  c  o  m*/
    index = str.indexOf('p');      // index will have a value of 1
    System.out.println(index);
    index = str.indexOf("pl");     // index will have a value of 2
    System.out.println(index);
    index = str.lastIndexOf('p');  // index will have a value of 2
    System.out.println(index);
    index = str.lastIndexOf("pl"); // index will have a value of 2
    System.out.println(index);
    index = str.indexOf("k");      // index will have a value of -1
    System.out.println(index);
  }
}

Result

Exercise

• Write code to search a char inside a string
• Write code to search index Of a char inside a string
• Write code to search a char in a char array
• Write code to Loop through the bounds of str starting at start and incrementally moves in the direction of adder. The loop searches for a single character in the bounds of str that is in the collection of characters.
• Write code to search char value in an array of char
• Write code to check if a string contains Any Of another string using variable length method
• Write code to check if a string contains Only another string array
• Write code to check if a string contains Any other string in an array using Stream
• Write code to check if a string value is contained in a string array
• Write code to Return true if a string array contains a given string.
• Write code to check if a string contains Special Character using regex
• Write code to Return a double-quoted String if the said String contains white-space.
• Write code to see if the given string contains any of the given terms.
• Write code to Test to see if the given string contains any of the given terms.
• Write code to Get the first index in a string that contains any of the char objects in characters.
• Write code to Get the last index in a string that contains any of the char objects in characters.
• Write code to check if a string contains Non Whitespace Characters
• Write code to check if an Array Contains a String
• Write code to check if a char array contains a certain char
• Write code to check if an array of char Contains a char
• Write code to Return the size of substring that does not contain any trailing spaces
• Write code to check if a string contains None of the char in the char array
• Write code to get Tab Indexes in side a string
• Write code to Return the index within the given string of the x. occurrence of the specified character.
• Write code to Return the index of the first whitespace character or '-' in line that is at or after start.
• Write code to Return the index of the first whitespace character or '-' in line that is at or before start.
• Write code to get the last Index Of Letter in a string
• Write code to get the first Index Of a Char
• Write code to get the index of an element in an array
• Write code to get nth Last Index Of
• Write code to Skip any spaces at or after start and returns the index of first non-space character;
• Write code to check char index Of Any But supplied char array in a string
• Write code to check the index Of Any char in the char array among a string
• Write code to get the index of Difference
• Write code to get last Index Of Any element in an array

• Previous
• Next