Convert string to title case in JavaScript

In this article, we will convert a string to a title case in such a way that every new word begins with a capital(uppercase) letter. 

This can be achieved in the following ways- 

• By using replace() function
• By using For loop to titlecase a string
• By using map() method
• By using reduce() method

By using replace() function: The replace() method in JavaScript is used to search a string for a value or any expression and replace it with the new value provided in the parameters. The original string is not changed by this method.

javascript

<script>
    function sentenceCase (str) {
    if ((str===null) || (str===''))
        return false;
    else
    str = str.toString();

    return str.replace(/\w\S*/g,
    function(txt){return txt.charAt(0).toUpperCase() +
        txt.substr(1).toLowerCase();});
    }

    console.log(sentenceCase('geeks for geeks'));
</script>

Output:

Geeks For Geeks

By using For loop to titlecase a string: In this method, the Javascript For loop is used to iterate over the arguments of the function and the characters are converted to Uppercase. 

javascript

<script>
    function titleCase(str) {
    str = str.toLowerCase().split(' ');
    for (var i = 0; i < str.length; i++) {
        str[i] = str[i].charAt(0).toUpperCase() + str[i].slice(1);
    }
    return str.join(' ');
    }
    console.log(titleCase("GEEKS FOR GEEKS"));
</script>

Output:

Geeks For Geeks

By using map() method: The Javascript map() method in JavaScript creates an array by calling a specific function on each element present in the parent array. It is a non-mutating method. Generally, the map() method is used to iterate over an array and calling function on every element of the array. 

javascript

<script>
    function titleCase(str) {
    return str.toLowerCase().split(' ').map(function(word) {
        return (word.charAt(0).toUpperCase() + word.slice(1));
    }).join(' ');
    }
    console.log(titleCase("converting string to titlecase"));
</script>

Output:

Converting String To Titlecase

By Using reduce() method: The Javascript arr.reduce() method in JavaScript is used to reduce the array to a single value and executes a provided function for each value of the array (from left-to-right) and the return value of the function is stored in an accumulator. But first we need to convert string into lowercase

Javascript

<script>
    function titleCase(st) {
      return st.toLowerCase().split(" ").reduce( (s, c) =>
      s +""+(c.charAt(0).toUpperCase() + c.slice(1) +" "), '');
    }
    console.log(titleCase("converting string to titlecase"));
</script>

Output:

Converting String To Titlecase