<\/span><\/h2>\n\n\n\nYou can use includes() function to check if a string contains a substring or not. It returns true if the substring is present in the string, else it returns false. It is commonly used by JavaScript for this purpose. Here is its syntax.<\/p>\n\n\n\n
string.incudes(substring,[position])<\/pre>\n\n\n\nThe includes function can be called on any string variable or literal. The first argument is the substring you need to search. The second argument is optional and means the starting point where you want to start the search from.<\/p>\n\n\n\n
Here is an example to check if substring ‘good’ is present in our string.<\/p>\n\n\n\n
a.includes('good'); \/\/ returns true<\/pre>\n\n\n\nPlease note, includes performs a case-sensitive search so if the substring is not in the proper case, then it will return false.<\/p>\n\n\n\n
a.includes('Good'); \/\/ returns false<\/pre>\n\n\n\nSo you can convert the original string to lower\/uppercase to match the case of your substring.<\/p>\n\n\n\n
console.log(a.toLowerCase().includes('Good'.toLowerCase())) \/\/ returns<\/pre>\n\n\n\nIn the above example, the original string and substring have different cases. So we convert both of them to lowercase before calling includes function. Please note, toLowerCase() does not alter the original string but only its copy used for checking.<\/p>\n\n\n\n
If your original string is very large and you have a vague idea about the location of substring, then you can specify the position argument that tells includes function where to start looking. But ensure that you do not start looking after the substring’s position.<\/p>\n\n\n\n
a.includes('good',2); \/\/ returns false<\/pre>\n\n\n\nIn the above example, we have specified position as 2, whereas the substring starts from 1st letter so the result is false.<\/p>\n\n\n\n