[SoyNuevo]

Hey, so you can't do stuff like

Code

Integer.parseInt(string.charAt(i));

because the parse method requires a string instead of a char.

However, if you do this:

Code

Integer.parseInt("" + string.charAt(i));

java thinks it is perfectly acceptable and accepts the char. because java reads left -> right

I'm wondering if this is good practice or if there is a specific way I should be converting my chars to strings. thanks

[FinnTheHuman]

In order to convert a char to a string you can simply use

String myString = new String(myChar);

[Stealth™]

OP, the method you currently use to parse a char into a String is an anti-pattern and should be avoided.

A proper way would consist of calling Character#toString.

[FeatureBug]

Code

Integer.parseInt("" + string.charAt(i));

Typically, you never want to be concatenating strings this way, even if it's just for a little hack-together like this.

A proper way would consist of calling Character#toString.

This is the best way to achieve what you want.

Do you use an IDE to develop in? I'm surprised it didn't recommend that function.

[Intel]

Hey, so you can't do stuff like

Code

Integer.parseInt(string.charAt(i));

because the parse method requires a string instead of a char.

However, if you do this:

Code

Integer.parseInt("" + string.charAt(i));

java thinks it is perfectly acceptable and accepts the char. because java reads left -> right

I'm wondering if this is good practice or if there is a specific way I should be converting my chars to strings. thanks

Just from what you're trying to do, converting an ascii char into an int:

PHP Code


<?php 
int x = (int) (string.charAt(i) - '0'); 


This would be a faster solution to what you're trying to do.

[Stealth™]

Just from what you're trying to do, converting an ascii char into an int:

PHP Code


<?php 
int x = (int) (string.charAt(i) - '0'); 


This would be a faster solution to what you're trying to do.

That's even worse than what OP has

[TCP]

You can even just do

Code

Integer.parseInt(string.substring(i,i+1));

[Not2EXceL]

You can even just do

Code

Integer.parseInt(string.substring(i,i+1));

Accessing the underlying char array via String#charAt(int) and converting via String#valueOf(char) or Character#toString(char) is faster

[TCP]

Accessing the underlying char array via String#charAt(int) and converting via String#valueOf(char) or Character#toString(char) is faster

I am getting different results with this

Code

String string = "number 5 is cool";
int i = 7, x;

long time = System.nanoTime();
x = Integer.parseInt(string.substring(i,i+1));
System.out.println(System.nanoTime()-time);

time = System.nanoTime();
x = Integer.parseInt(Character.toString(string.charAt(i)));
System.out.println(System.nanoTime()-time);

The first version is running faster with Java 8+ on my pc but when I put it online it is slower

[matt]

I am getting different results with this

Code

String string = "number 5 is cool";
int i = 7, x;

long time = System.nanoTime();
x = Integer.parseInt(string.substring(i,i+1));
System.out.println(System.nanoTime()-time);

time = System.nanoTime();
x = Integer.parseInt(Character.toString(string.charAt(i)));
System.out.println(System.nanoTime()-time);

The first version is running faster with Java 8+ on my pc but when I put it online it is slower

there's no need to micro-optimize, just keep it simple and up to date procedure.

[Chickendipper]

I am getting different results with this

Code

String string = "number 5 is cool";
int i = 7, x;

long time = System.nanoTime();
x = Integer.parseInt(string.substring(i,i+1));
System.out.println(System.nanoTime()-time);

time = System.nanoTime();
x = Integer.parseInt(Character.toString(string.charAt(i)));
System.out.println(System.nanoTime()-time);

The first version is running faster with Java 8+ on my pc but when I put it online it is slower

This is literally the worst benchmark in all of existence.

1. You're doing 1 iteration
   


2. You only ran it once(?)
   


3. The JVM will not have had time to make necessary optimisations
   


4. You're comparing run times from your computer to a fully loaded online java compiler
   

For more, read this and then create a proper benchmark.

@OP: "" + char is bad practice. Why? When you do:
string1 + string2
in Java, what's actually happening (when compiled, under the hood) is:
new StringBuilder().append(string1).append(string2).toString()
So we're creating a new StringBuilder object. This takes up memory, so we're using up more memory than we wanted (yes, the GC will eventually get to it, but it's still bad practice).
Furthermore, doing:
string1 + object1 (where object1 is anything BUT a string)
in Java, this happens instead:
new StringBuilder().append(string1).append(object1.toString()).toString()
Thus we're creating a new object and invoking the #toString() method created by the superclass of object1. We're using up a lot more resources than we need.
The preferred solution would be to, for example, use Character.toString(char).

[TCP]

This is literally the worst benchmark in all of existence.

Was not a benchmark just a test, every time I ran it myself the first solution was faster, same with multiple iterations in a loop

My point is there is no really a faster solution as the other guy said because it depends on environment

.charAt() is better for readability in such a context