Check string in string javascript
ExamplesCheck if a string includes "world": Show
let text = "Hello world, welcome to the universe."; Try it Yourself » let text = "Hello World, welcome to the universe."; Try it Yourself » More examples below. Definition and UsageThe Otherwise it returns The Syntaxstring.includes(searchvalue, start) Parameters
Return Value
More ExamplesStart at position 12: let text = "Hello world, welcome to the universe."; Try it Yourself » Browser Support
ES6 (JavaScript 2015) is supported in all modern browsers:
Another alternative is KMP (Knuth–Morris–Pratt). The KMP algorithm searches for a length-m substring in a length-n string in worst-case O(n+m) time, compared to a worst-case of O(n⋅m) for the naive algorithm, so using KMP may be reasonable if you care about worst-case time complexity. Here's a JavaScript implementation by Project Nayuki, taken from https://www.nayuki.io/res/knuth-morris-pratt-string-matching/kmp-string-matcher.js: The Parameters
A string to be searched for within position OptionalThe position within the string at which to begin searching for Return value
ExceptionsDescriptionThis method lets you determine whether or not a string includes another string. Case-sensitivityThe You can work around this constraint by transforming both the original string and the search string to all lowercase: ExamplesUsing includes()Specifications
Browser compatibilityBCD tables only load in the browser See alsoHow do you check if a string contains a string in JavaScript?To check if a substring is contained in a JavaScript string:
Call the indexOf method on the string, passing it the substring as a parameter - string. indexOf(substring) Conditionally check if the returned value is not equal to -1. If the returned value is not equal to -1 , the string contains the substring.
How do you check if a string contains a character JavaScript?In JavaScript, 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.
Can we use == to compare strings in JavaScript?In JavaScript, strings can be compared based on their “value”, “characters case”, “length”, or “alphabetically” order: To compare strings based on their values and characters case, use the “Strict Equality Operator (===)”.
Is string check in JavaScript?Check if a Variable is a String in JavaScript #
We used the typeof operator to check if a variable is a string. The operator returns a string that indicates the type of the value. Copied! If the variable stores a string, the equality condition will return true and the if block will run.
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