How to Check Whether an Array Contains a String in TypeScript ?
To check whether an array contains a string in typescript we have a different approach. In this article, we are going to learn how to check whether an array contains a string in typescript.
Below are the approaches to check whether an array contains a string in typescript:
Table of Content
- Approach 1: Using Array.includes() method
- Approach 2: Using Array.indexOf() method
- Approach 3: Using Array.some() method
- Approach 4: Using Array.find() method
- Approach 5: Using Array.find() method with a boolean condition
Approach 1: Using Array.includes() method
The includes
method is a straightforward way to check if an array contains a specific value, including strings.
Syntax:
const arrayContainsString = myArray.includes("yourString");
Example: In this example, we are using Array.include() method.
const myArray: string[] = ["apple", "banana",
"orange"];
if (myArray.includes("banana")) {
console.log(`Array contains the
string 'banana'.`);
} else {
console.log(`Array does not contain
the string 'banana'.`);
}
Output:
Array contains the string 'banana'.
Approach 2: Using Array.indexOf() method
The indexOf
method returns the index of the first occurrence of a specified element in an array. If the element is not present, it returns -1.
Syntax:
const index = myArray.indexOf("yourString");
const arrayContainsString = index !== -1;
Example: In this example, we are using Array.indexof() method.
const myArray: string[] = ["apple",
"banana", "orange"];
const searchString: string = "banana";
if (myArray.indexOf(searchString) !== -1) {
console.log(`Array contains the
string '${searchString}'.`);
} else {
console.log(`Array does not contain
the string '${searchString}'.`);
}
Output:
Array contains the string 'banana'.
Approach 3: Using Array.some() method
The some
method tests whether at least one element in the array passes the provided function.
Syntax:
const arrayContainsString = myArray.some(item => item === "yourString");
Example: In this example, we are using Array.some() method.
const myArray: string[] = ["apple",
"banana", "orange"];
const searchString: string = "banana";
if (myArray.some(item => item === searchString)) {
console.log(`Array contains
the string '${searchString}'.`);
} else {
console.log(`Array does not
contain the string '${searchString}'.`);
}
Output:
Array contains the string 'banana'.
Approach 4: Using Array.find() method
The find() method returns the value of the first element in the provided array that satisfies the provided testing function. Otherwise, it returns undefined.
Syntax:
const foundString = myArray.find(item => item === "yourString");
const arrayContainsString = foundString !== undefined;
Example: In this example, we are using Array.find() method.
const myArray: string[] = ["apple", "banana", "orange"];
const searchString: string = "banana";
const foundString = myArray.find(item => item === searchString);
if (foundString) {
console.log(`Array contains the string '${searchString}'.`);
} else {
console.log(`Array does not contain the string '${searchString}'.`);
}
Output:
Array contains the string 'banana'.
Approach 5: Using Array.find() method with a boolean condition
The Array.find() method can be utilized with a boolean condition to check if an array contains a specific string. This approach returns the found string if it exists in the array, otherwise returns undefined.
Example: In this example, we’ll use the Array.find() method with a boolean condition to determine if an array contains a string.
const myArray: string[] = ["apple", "banana", "orange"];
const searchString: string = "banana";
const foundString = myArray.find(item => item === searchString);
if (foundString) {
console.log(`Array contains the string '${searchString}'.`);
} else {
console.log(`Array does not contain the string '${searchString}'.`);
}
Output
Array contains the string 'banana'.
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