c#: string format

Question

I came across a code. Can anybody shed a bit of light on it. Plz be kind if anybody finds it a bit basic. ``` string str= String.Format("{0,2:X2}", (int)value); ``` Thankyou for your time.

Accepted Answer

`X` format returns Hexadecimal representation of your `value`.

for example `String.Format("{0:X}", 10)` will return `"A"`, not `"10"`

`X2` will add zeros to the left, if your hexadecimal representation is less than two symbols

for example `String.Format("{0:X2}", 10)` will return `"0A"`, not `"A"`

`0,2` will add spaces to the left, if the resulting number of symbols is less than 2.

for example `String.Format("{0,3:X2}", 10)` will return `" 0A"`, but not `"0A"`

So as result this format `{0,2:X2}` will return your value in Hexadecimal notation appended by one zero from the left if it is only one symbol and then appended by space from the left if is it one symbol. After reading this several times, you can see, that `,2` is redundant and this format can be simplified to `{0:X2}` without changing the behavior.

Some notes:

`:` separates indexing number and specific format applied to that object. For example this code

```
String.Format("{0:X} {1:N} {0:N}", 10, 20)
```

shows, that I want to format `10` (index 0) in hexadecimal then show `20` (index 1) in numerical way, and then also format `10` (index 0) in numeric way.

`0,2` from the left part of semi-column indicated index position `0` and format `,2` applied to the resulting string, not to a specific object. So this code

```
String.Format("{0,1} {1,2} {0,4}", 10, 20)
```

will print first number with at least one symbol, second with at least two symbols and then again first number with at least four symbols occupied. If the number of symbols in resulting string will be less - they will be populated by spaces.

c#: string format

Solution

Problem