JavaScript: Make capitalize the first letter of each word in a string

JavaScript String: Exercise-9 with Solution

Capitalize Each Word

Write a JavaScript function to capitalize the first letter of each word in a string.

Test Data:
console.log(capitalize_Words('js string exercises'));
"Js String Exercises"

Visual Presentation:

Sample Solution:

JavaScript Code:

// Define a function named capitalize_Words that takes a string str as input
function capitalize_Words(str)
{
  // Use the replace method with a regular expression to match words (\w) followed by zero or more non-space characters (\S*)
  // For each matched word, use a callback function to capitalize the first character and convert the rest of the characters to lowercase
  return str.replace(/\w\S*/g, function(txt){return txt.charAt(0).toUpperCase() + txt.substr(1).toLowerCase();});
}
// Call the capitalize_Words function with the argument 'js string exercises' and output the result
console.log(capitalize_Words('js string exercises'));

Output:

Js String Exercises

Explanation:

In the exercise above,

• The function "capitalize_Words()" is defined with a single parameter 'str', representing the input string.
• Within the function, a regular expression (/\w\S*/g) is used with the "replace()" method to match words in the string.
• For each matched word, a callback function is invoked, which capitalizes the first character using 'txt.charAt(0).toUpperCase()' and converts the rest of the characters to lowercase using 'txt.substr(1).toLowerCase()'.
• The "replace()" method replaces each matched word with the modified version (capitalized first letter and lowercase rest).
• Finally, the modified string is returned from the function.

Flowchart:

Live Demo:

See the Pen JavaScript Make capitalize the first letter of each word in a string - string-ex-9 by w3resource (@w3resource) on CodePen.

For more Practice: Solve these Related Problems:

• Write a JavaScript function that splits a string into words, capitalizes the first letter of each, and rejoins them.
• Write a JavaScript function that uses map() to process each word and convert its first character to uppercase.
• Write a JavaScript function that handles punctuation and ensures only alphabetical characters are capitalized.
• Write a JavaScript function that converts a sentence to title case using regular expressions and string replacement.

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