Title Case a Sentence

Heggy Castaneda
Jul 22, 2017 · 2 min read
# Return the provided string with the first letter of each word capitalized. Make sure the rest of the word is in lower case.

Capitalize first letter in each word a string. Start with string and end with string.

I want to break down what FCC Basic Code Solution:

String.prototype.replaceAt = function(index, character) {
return this.substr(0, index)
+ character
+ this.substr(index + character.length);
function titleCase(str) { var newTitle = str.split(' ');
var updatedTitle = [];
for (var st in newTitle) { updatedTitle[st] =
.replaceAt(0, newTitle[st].charAt(0).toUpperCase());
return updatedTitle.join(' ');

First, let’s brush upon for..in loop.

var fccCamperObj = {
nameKey: "heggy",
hobbyKey: "drinking boba tea",
catLoverKey: true
// iterate through obj, return key => value
// ex: name => heggy, hobby => drinking boba tea, catLover => true
// generic format of for..in loop: for (var key in object)
for (var key in fccCamperObj) {
// key below is same variable key inside of for loop parenthesis console.log(key + ' => ' + fccCamperObj[key]);

Note 1: key is a variable therefore we use bracket notation (not dot notation) to get the value. fccCamperObj[key]

Note 2: key is a variable that gets assigned to each property key inside of object fccCamperObj.


nameKey => heggy
hobbyKey => drinking boba tea
catLoverKey => true

function titleCase(str) {  var newTitle = str.split(' ');  var updatedTitle = [];  // for...in obj iteration for (var key in obj)  for (var position in newTitle) {  // newTitle[position]  // .replaceAt custom-made method called with index = 0 and first char becoming upperCase ('T')  // newTitle[position].charAt(0) => extract single charAt position 0 (output: t from tea)  // updateTitle[position] each position get new word inside arrayupdatedTitle[position] = newTitle[position].toLowerCase().replaceAt(0, newTitle[position].charAt(0).toUpperCase());}// .join change updateTitle back into string from array of str// .join(' ') joins with spacing in betwnreturn updatedTitle.join(' ');}// when updatedTitle[position] is called this custom-made replaceAt method is called.
// Let's say we are on 'tea' on our array.
// newTitle[position].toLowerCase().replaceAt(0, 'T')
// newTitle[3] = tea, .charAt(0) grab first element of
// tea => 't', then make it toUpperCase letter 'T'
// note: newTitle[position].charAt(0).toUpperCase() => 'T'
String.prototype.replaceAt = function(index, character) {// 'this' stands for newTitle[position] element of object in our array
// since it is method chained in a following manner
// newTitle[position].toLowerCase().replaceAt(0, 'T')
// newTitle[position] => newTitle[3] = tea in our current example.
// this.substr (0, index = 0)
// substr (0, number of char to extract = 0) => substr(0,0) means start at 0 but extract none(0)
// character = 'T' from newTitle[position].charAt(0).toUpperCase() means grab first character and make it upperCase
// this.substr(0 + 1 = 1) => extract string start at index 1, (no second argument defaults grab the rest)
// output: Teareturn this.substr(0, index) + character + this.substr(index + character.length);};// uncomment debugger below to run through it in console
// debugger;
titleCase("I'm a little tea pot");

Heggy Castaneda

Written by

like to build things

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