Alternate Replacement of ParseInt in java ?

[Prabhat Ranjan]

Implementation of parseInt() methods in java..

i don't want to use this method and also as the code written in Integer class of Lang package is much harder to understand.

so is it possible to write simple code for replacement of ParseInt() method..

like

int myOwnParseInt(String args) {

// i want the implementation of of parseInt

}

 

[Pushkar Choudhary]

 

Prabhat Ranjan wrote:
i don't want to use this method and also as the code written in Integer class of Lang package is much harder to understand.

Well, you could mention the part that you didn't understand and people here will try to help you with it.

[Rob Spoor]

Why would you want to rewrite something that has been working just fine for over a decade?

That said, it's not really hard to write a simple parse method:

public int parse(String src)
{
int start = 0; // where to start iterating
boolean negative = false; // negative or not
switch (src.charAt(0))
{
case '-':
negative = true;
start = 1;
break;
case '+':
start = 1;
break;
// default: do nothing
}
int number = 0;
for (int i = start; i < src.length(); i++)
{
number = number * 10 + Character.digit(src.charAt(i), 10);
}
if (negative)
{
number = -number;
}
return number;
}

This quick code has a few flaws:
- there is no checking on empty strings, or only sign symbols
- there is no overflow checking
- there is no check if each character is a digit

That shouldn't be too hard to add though.

[Prabhat Ranjan]

Ok thanks ! i will test this code !

[David Newton]

 

Prabhat Ranjan wrote:i don't want to use this method and also as the code written in Integer class of Lang package is much harder to understand.

There's probably a *lot* of code in the JDK that's hard to understand--why not just view them as black boxes? Why does it matter that code you almost never look at is difficult to understand?

If you just *want* to write your own versions of code that already works, that's one thing (although a relatively low return on investment--if my boss caught me re-writing JDK code I'd be in trouble).