JavaScript: Strip leading and trailing spaces from a string

JavaScript String: Exercise-23 with Solution

Trim Spaces

Write a JavaScript function to strip leading and trailing spaces from a string.

Test Data:
console.log(strip('w3resource '));
console.log(strip(' w3resource'));
console.log(strip(' w3resource '));
Output :
"w3resource"
"w3resource"
"w3resource"

Sample Solution:

JavaScript Code:

// Define a function named strip that removes leading and trailing whitespaces from a string
function strip(str) {
    // Use the replace method with a regular expression to remove leading and trailing whitespaces
    return str.replace(/^\s+|\s+$/g, '');
}

// Test the strip function with various input strings and log the results
console.log(strip('w3resource '));     // Output: 'w3resource'
console.log(strip(' w3resource'));     // Output: 'w3resource'
console.log(strip(' w3resource  '));   // Output: 'w3resource'

Output:

w3resource
w3resource
w3resource.

Explanation:

In the exercise above,

• function strip(str) {: This line declares a function named "strip()" that takes a string 'str' as input.
• return str.replace(/^\s+|\s+$/g, '');: This line uses the "replace()" method with a regular expression to remove leading and trailing whitespaces (\s represents whitespace characters). The regular expression ^\s+ matches one or more whitespace characters at the beginning of the string, and \s+$ matches one or more whitespace characters at the end of the string. The 'g' flag ensures that all occurrences of leading and trailing whitespaces are replaced with an empty string, effectively removing them.
• }: This line closes the function definition.
• The subsequent console.log statements test the "strip()" function with different input strings and output the results.

Flowchart:

Live Demo:

See the Pen JavaScript Strip leading and trailing spaces from a string - string-ex-23 by w3resource (@w3resource) on CodePen.

For more Practice: Solve these Related Problems:

• Write a JavaScript function that removes leading and trailing whitespace from a string using regex.
• Write a JavaScript function that uses the built-in trim() method and also handles multiple spaces between words.
• Write a JavaScript function that validates the input type and returns an error if the value is not a string.
• Write a JavaScript function that compares the results of manual trimming versus built-in methods for consistency.

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