TypeScript String search() Method

The search() method is an inbuilt function in TypeScript that is used to search for a match between a regular expression and a string. It returns the index of the first match, or -1 if no match is found.

Syntax

string.search(regexp);

Parameter

This methods accept a single parameter as mentioned above and described below: 

• regexp: This parameter is a RegExp object.

Return Value:

• The method returns the index of the regular expression inside the string. If no match is found, it returns -1.

Examples of TypeScript String search() Method

Example 1: Finding a Substring with search()

In this example, we use the search() method to find the position of a substring that matches a regular expression.

let str: string = "Hello, welcome to TypeScript!";
let index: number = str.search(/welcome/);

if (index !== -1) {
    console.log("Found at index:", index);
} else {
    console.log("Not Found");
}

Output: 

Found at index: 7

Example 2: No Match Found with search()

In this example, we use the search() method to look for a substring that does not exist in the string.

let str: string = "Hello, welcome to TypeScript!";
let index: number = str.search(/world/);

if (index !== -1) {
    console.log("Found at index:", index);
} else {
    console.log("Not Found");
}

Output:

Not Found