trying to write a function that takes a string, and returns the string back with first letter of each word in capital. i am able to do so. But i keep on getting undefined value at my first index value in the iteration, tho the i have items in my list.
i wrote my function that takes a string parameter. i pass my parameter in to split using split(" ") method it so i can get an array of words. and when i created my forloop to go over all of them to be able to make each of their first letters Capital. now in the iteration, i create a variable to store the first index element converted into a string using the toString() method so i can later apply the toUpperCase() method on it
When i do a console.log() in the for loop i can see the elements converted all listed out (when i execute the function and pass a string to it)
But i do not understand why i get: Uncaught TypeError: Cannot read property 'toString' of undefined...and this error points to the variable holding the element at index [i] when i am converting it to string in the forloop: var pickString = newStringList[i].toString()
function capitalizeLertters (letter) {
var newStringList = letter.split(" ");
// console.log(newStringList[0])
var addAll = []
for (var i = 0; i <= newStringList.length; i++) {
console.log(newStringList[i])
var pickString = newStringList[i].toString()
// console.log(pickString)
var finalString = pickString.charAt(0).toUpperCase() + pickString.slice(1)
// console.log(finalString)
}
addAll.push(finalString)
// console.log(addAll)
return addAll
}
console.log(capitalizeLertters("js string exercises"))
This is my expected result: "Js String Exercises"
And these are the different console.log results
""js Js string String exercises Exercises""
But my function does not execute in the end...it throws this:
"""learnJs.js:100 Uncaught TypeError: Cannot read property 'toString' of undefined at capitalizeLertters (learnJs.js:100) at learnJs.js:110"""
So
You don't need toString()
on a String
The for loop crashes at the last element because you should stop at length -1
or simply replace <=
with <
.
You are calling addAll
after the loop, so it only adds the last element.
You are returning an array and I assume you want the String, so you can use join()
on the array.
function capitalizeLertters (letter) { var newStringList = letter.split(" "); var addAll = []; for (var i = 0; i < newStringList.length; i++) { var pickString = newStringList[i]; var finalString = pickString.charAt(0).toUpperCase() + pickString.slice(1); addAll.push(finalString); } return addAll.join(" "); } console.log(capitalizeLertters("js string exercises"))
please check the modifications
Solution :
function capitalizeLertters (letter) {
var newStringList = letter.split(" ");
// console.log(newStringList[0])
var addAll = [];
for (var i = 0; i < newStringList.length; i++) {
console.log(newStringList[i]);
var pickString = newStringList[i];
// console.log(pickString)
var finalString = pickString.charAt(0).toUpperCase() + pickString.slice(1);
// console.log(finalString)
addAll.push(finalString);
}
// console.log(addAll)
return addAll.join(" ");
}
capitalizeLertters("js string exercises");
An array starts with the index number 0. The length of newStringList is 3. If you give a less than (<) then 'i' will go like 0("js"), 1("string"), 2("exercises"). If you give a less than equal (<=) it will go like 0("js"), 1("string"), 2("exercises"), 3(undefined).
function capitalizeLertters (letter) {
var newStringList = letter.split(" ");
var addAll = ""
for (var i = 0; i < newStringList.length; i++) {
var pickString = newStringList[i].toString()
var finalString = pickString.charAt(0).toUpperCase() + pickString.slice(1)
addAll += finalString
if(i != newStringList.length-1){
addAll +=" "
}
}
return addAll
}
console.log(capitalizeLertters("js string exercises"))
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