Simple function java String to Int / Reverse

Question

I want to generate a String with 11 digits from an ID.
For example: an account with an ID=12 would give 00000000012

And after that I need to retrieve this id from the string.

For example: a string with 00000000022 give an ID=22

icyrock.com · Accepted Answer · 2012-02-25 04:00:07Z

7

To format the string, use String.format:

int n = 123;
String.format("%011d", 123);
// ===> 00000000123

To get the number back from string, use Integer.parseInt:

Integer.parseInt("00000000123");
// ====> 123

answered Feb 25, 2012 at 4:00

icyrock.com

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Comments

Hawken · Accepted Answer · 2012-02-25 04:13:56Z

0

As mentioned in the other answer from String to int use Integer.parseInt()

However, for creating the String I would suggest:

for(int x=0;x<10;x++){
    thestring="0"+thestring;
}

replace 10 with how many zeros you need.

Also you could just use java.text.DecimalFormat, your choice.

Or combine both:

int lengthID=10;
String zeros="";
for(int x=0;x<lengthID;x++){
    zeros="0"+zeros;
}
java.text.DecimalFormat id=new java.text.DecimalFormat(zeros);

answered Feb 25, 2012 at 4:13

Hawken

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thestring="0"+thestring; is very costly