The matchAll() method provides an iterator that holds the outcomes of matching a string against another string or a regular expression.
Example
| const iterator = text.matchAll(“Cats”); |
If the parameter is a regular expression, it is necessary to set the global flag (g); otherwise, a TypeError will be thrown.
Example
| const iterator = text.matchAll(/Cats/g); |
To conduct a case-insensitive search, ensure the insensitive flag (i) is set.
Example
| const iterator = text.matchAll(/Cats/gi); |
|
Note matchAll() is a feature introduced in ES2020. However, it does not function in Internet Explorer. |
The includes() method returns true if a specified value is found within a string; otherwise, it returns false.
Examples
Verify whether a string contains “world”.
| let text = “Hello world, welcome to the universe.”; text.includes(“world”); |
Check if a string includes “world”, beginning from position 12.
| let text = “Hello world, welcome to the universe.”; text.includes(“world”, 12); |
|
Note includes() is case-sensitive. includes() is a feature introduced in ES6. includes() lacks support in Internet Explorer. |
The startsWith() method returns true if a string commences with a specified value; otherwise, it returns false.
Examples
Returns true:
| let text = “Hello world, welcome to the universe.”; text.startsWith(“Hello”); |
Returns false:
| let text = “Hello world, welcome to the universe.”; text.startsWith(“world”) |
You can specify a starting position for the search.
Returns false:
| let text = “Hello world, welcome to the universe.”; text.startsWith(“world”, 5) |
Returns true:
| let text = “Hello world, welcome to the universe.”; text.startsWith(“world”, 6) |
|
Note startsWith() is sensitive to case. startsWith() is a feature introduced in ES6. startsWith() is not compatible with Internet Explorer. |
The endsWith() method returns true if a string concludes with a specified value.
otherwise, it returns false.
Example
Verify whether a string concludes with “Doe”.
| let text = “John Doe”; text.endsWith(“Doe”); |
Verify whether the first 11 characters of a string conclude with “world”.
| let text = “Hello world, welcome to the universe.”; text.endsWith(“world”, 11); |
|
Note endsWith() is sensitive to case. endsWith() is a feature introduced in ES6. endsWith() is not compatible with Internet Explorer. |