In this article, we will write programs to check all possible matching in JavaScript. We will check the occurrence of characters individually in the given string or sequence. In this article, we will check the occurrence of vowels in the given string.
Table of Content
Approach 1: Using JavaScript RegExp test() Method
The RegExp test() Method in JavaScript is used to test for the match in a string. If there is a match this method returns true else it returns false.
Syntax:
RegExpObject.test( str )
Example: This example illustrates matching a single character with Multiple possibilities using the RegExp test() Method.
// Create input string let string = "GeeksforGeeks" ;
// Create global regular expression // containing letters to be matched let regx = /[aeiou]/g; // Store results from RegX test method let result = regx.test(string); // Display the result console.log(result); |
true
Approach 2: Using JavaScript String match() Method
The JavaScript String match() method is an inbuilt function in JavaScript used to search a string for a match against any regular expression. If the match is found, then this will return the match as an array.
Syntax:
string.match( regExp );
Example: This example illustrates matching a single character with Multiple possibilities using the String match() Method
// Create input string let string = "GeeksforGeeks" ;
// Create global regular expression // containing letters to be matched let regx = /[aeiou]/g; // Store results from string match method let result = [...string.match(regx)]; // Display the result console.log(result); |
[ 'e', 'e', 'o', 'e', 'e' ]
Approach 3: Using JavaScript String includes() Method
JavaScript String includes() method determines whether a string contains the given characters within it or not. This method returns true if the string contains the characters, otherwise, it returns false.
Syntax:
string.includes(searchvalue, start);
Example: This example illustrates matching a single character with Multiple possibilities using the includes() Method.
// Create a input string let string = "GeeksforGeeks" ;
// The letters to be matched const character = "aeiou" ;
// To store the letters found result = []; // Split character string and iterate character.split( "" ).some((char) => {
// Check if character is present
if (string.includes(char))
// Store the characters
result.push(char);
}); // Display the result console.log(result); |
[ 'e', 'o' ]
Approach 4: Using JavaScript String indexOf() Method
The JavaScript String indexOf() method finds the index of the first occurrence of the argument string in the given string. The value returned is 0-based.
Syntax:
str.indexOf(searchValue , index);
Example: This example illustrates matching a single character with Multiple possibilities using the String indexOf() Method.
// Create a input string let string = "JavaScript" ;
// The letters to be matched const character = "aeiou" ;
// To store the letters found result = []; // Iterate the characters to apply // indexOf at each one Array.from(character).some((char) => { if (string.indexOf(char) !== -1)
// Store the found character
result.push(char);
}); // Display the result console.log(result); |
[ 'a', 'i' ]