how to check if a string contains a substring code example

Example 1: javascript string contains

var string = "foo",
    substring = "oo";

console.log(string.includes(substring));

Example 2: check if string contains substring

Like this:

if (str.indexOf("Yes") >= 0)
...or you can use the tilde operator:

if (~str.indexOf("Yes"))
This works because indexOf() returns -1 if the string wasn't found at all.

Note that this is case-sensitive.
If you want a case-insensitive search, you can write

if (str.toLowerCase().indexOf("yes") >= 0)
Or:

if (/yes/i.test(str))

Example 3: javascript check if string contains a text substring

stringVariable.includes("Your Text");

Example 4: find a substring in a string java

package hello;

public class SubStringProblem {

  public static void main(String[] args) {

    // 1st example - You can use the indexOf() method to check if
    // a String contains another substring in Java
    // if it does then indexOf() will return the starting index of
    // that substring, otherwise it will return -1

    System.out
        .println("Checking if one String contains another String using indexOf() in Java");
    String input = "Java is the best programming language";
    boolean isPresent = input.indexOf("Java") != -1 ? true : false;

    if (isPresent) {
      System.out.println("input string: " + input);
      System.out.println("search string: " + "Java");
      System.out.println("does String contains substring? " + "YES");
    }

    // indexOf is case-sensitive so if you pass wrong case, you will get wrong
    // result
    System.out.println("Doing search with different case");
    isPresent = input.indexOf("java") != -1 ? true : false;
    System.out.println("isPresent: " + isPresent); // false because indeOf() is
                                                   // case-sensitive

    // 2nd example - You can also use the contains() method to check if
    // a String contains another String in Java or not. This method
    // returns a boolean, true if substring is found on String, or false
    // otherwise.
    // if you need boolean use this method rather than indexOf()
    System.out
        .println("Checking if one String contains another String using contains() in Java");
    input = "C++ is predecessor of Java";
    boolean isFound = input.contains("Java");
    if (isFound) {
      System.out.println("input string: " + input);
      System.out.println("search string: " + "Java");
      System.out.println("does substring is found inside String? " + "YES");
    }

    // contains is also case-sensitive
    System.out.println("Searching with different case");
    isFound = input.contains("java");
    System.out.println("isFound: " + isFound); // false because indeOf() is
                                               // case-sensitive

  }
}

Output
Checking if one String contains another String using indexOf() in Java
input string: Java is the best programming language
search string: Java
does String contain substring? YES
Doing search with different case
isPresent: false
Checking if one String contains another String using contains() in Java
input string: C++ is the predecessor of Java
search string: Java
does substring is found inside String? YES
Searching for different case
isFound: false

Example 5: python check if value in string

def is_value_in_string(value: str, the_string: str):
    return value in the_string.lower()

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