How to take a string and return the capitalized format of a word

Question

int length = s.length();

if (length = 0){
    return s;
}

else {
    return s.charAt(0).toUpperCase()+ s.substring(1);
}

I get two errors saying:

if (length = 0){
^^^^^^^^^^
Type mismatch: cannot convert from int to boolean


return s.charAt(0).toUpperCase()+ s.substring(1);
       ^^^^^^^^^^^^^^^^^^^^^^^^^
Cannot invoke toUpperCase() on the primitive type char

Plus, if it's an empty sting it should just return it. That's why I'm using an If-Else statement.

Answer 1

if (length = 0) should be if (length == 0)

You're assigning the value 0 to length and not comparing it to 0.

I recommend you to take a look at this :

At run time, the result of the assignment expression is the value of the variable after the assignment has occurred. The result of an assignment expression is not itself a variable.

This way, your if is never satisfied since the value inside it evaluated to the value of the assigned (0 in this case), so your program goes to the else , and there you should:

return Character.toUpperCase(s.charAt(0)) + s.substring(1);

Answer 2

In your if statement, you are assigning the value 0 to length . Because of this your compiler is complaining, because it expects a boolean expression, and not an int in the if statement (assignment returns the value it is assigning, which is why it mentions the int ).

You mean to be evaluating a boolean expression by using == instead.

The second issue is because charAt(int) returns a char primitive, which doesn't have any methods.

In this case you probably want to utilize Character.toUpperCase(char) on the first character of your String and appending the rest.

Answer 3

you're missing the == in the if statement

charAt(0) returns a char, one way to make this a string is Character.toString(c)

Answer 4

Change it to this:

if (length == 0) {
    return s;
}

return Character.toUpperCase(s.charAt(0)) + s.substring(1);

Note: if the length of the string is exactly 1, you'll still get an error, because of s.substring(1) . You might want to add an additional condition for when the length of the string is exactly 1.

Answer 5

This line:

if (length = 0) {

means " I want to set the length to zero ". But what you want is

if (length == 0) {

which means " Is the length equal to zero? "

The first statement eventually results into an exception as you're passing an integer into a place where boolean is expected.

Answer 6

Maybe you can try this:

String s = "testing";
String upper = s.toUpperCase();
System.out.print(upper);