What is the string.substring() method in TypeScript?
Overview
TypeScript is the parent of JavaScript, and they both have similar methods. In fact, anywhere JavaScript runs, TypeScript runs as well. With the substring() method, we can extract a certain part of a string by specifying where to start and end the extraction.
Syntax
string.substring(start, end)
The syntax for the substring() method in TypeScript
Parameters
start: This is an integer. It represents the index position in the string from where we want to start the extraction.
end: This is also an integer that represents the end position where the extraction should stop.
Return value
A string is returned, which contains the extracted characters.
Example
export {}// create some stringslet name:string = "Theodore"let role:string = "Software Developer"let hubby:string = "Coding, Writing, Reading"// extract parts of the stringslet extract1 = name.substring(0, 3)let extract2 = role.substring(9, 12)let extract3 = hubby.substring(8, 15)// print the extracted substringsconsole.log(extract1)console.log(extract2)console.log(extract3)
Explanation
- Line 1: We export our code as a module. This is to prevent any problem related to variable scoping.
- Lines 4–6: We create three strings.
- Lines 9–11: We extract the
substringsby setting the start and end index values. Then we save the results to some variables. - Lines 14–16: Finally, we print the extracted
substringsto the console.