# How to Pad an Integer Number With Leading Zeroes in C#?

• Last Updated : 26 May, 2020

Given a Number N, the task is to pad this number with P number of leading zeros in C#.

Examples:

```Input: N = 123 , P = 4
Output: 0123

Input: N = -3 , P = 5
Output: -00003
```

Method 1: Using string Format() method : The Format() method is used to replace one or more format items in the specified string with the string representation of a specified object.

Step 1: Get the Number N and number of leading zeros P.

Step 2: Convert the number to string and to pad the string, use the string.Format() method with the formatted string argument “{0:0000}” for P= 4.

```val = string.Format("{0:0000}", N);
```

Step 3: Return the padded string.

Example :

## C#

 `// C# program to pad an integer``// number with leading zeros``using` `System;`` ` `class` `GFG{``     ` `    ``// Function to pad an integer number ``    ``// with leading zeros``    ``static` `string` `pad_an_int(``int` `N, ``int` `P)``    ``{``        ``// string used in Format() method``        ``string` `s = ``"{0:"``;``        ``for``( ``int` `i=0 ; i

Output:

```Before Padding: 123
```

Method 2: Using ToString() method : The ToString() method is used to convert the numeric value of the current instance to its equivalent string representation.

Step 1: Get the Number N and number of leading zeros P.

Step 2: Convert the number to string using the ToString() method and to pad the string use the formatted string argument “0000” for P= 4.

```val = N.ToString("0000");
```

Step 3: Return the padded string.

Example :

## C#

 `// C# program to pad an integer``// number with leading zeros``using` `System;`` ` `public` `class` `GFG{``     ` `    ``// Function to pad an integer number ``    ``// with leading zeros``    ``static` `string` `pad_an_int(``int` `N, ``int` `P)``    ``{``        ``// string used in ToString() method``        ``string` `s = ``""``;``        ``for``( ``int` `i=0 ; i

Output:

```Before Padding: 123
```

Method 3: Using PadLeft() method : The PadLeft() method is used to right-aligns the characters in String by padding them.

Step 1: Get the Number N and number of leading zeros P.

Step 2: Convert the number to string using the ToString() method.

```val = N.ToString();
```

```pad_str = val.PadLeft(P, '0');
```

Step 4: Return the padded string.

Example :

## C#

 `// C# program to pad an integer``// number with leading zeros``using` `System;`` ` `public` `class` `GFG{``     ` `    ``// Function to pad an integer number ``    ``// with leading zeros``    ``static` `string` `pad_an_int(``int` `N, ``int` `P)``    ``{``        ``// use of ToString() method``        ``string` `value = N.ToString();``         ` `        ``// use of the PadLeft() method``        ``string` `pad_str = value.PadLeft(P, ``'0'``);``         ` `        ``// return output``        ``return` `pad_str;``    ``}``     ` `    ``// driver code``    ``public` `static` `void` `Main(``string``[] args)``    ``{``        ``int` `N = 123; ``// Number to be pad``        ``int` `P = 5; ``// Number of leading zeros``         ` `        ``Console.WriteLine(``"Before Padding: "` `+ N);``         ` `        ``// Function calling``        ``Console.WriteLine(``"After Padding: "` `+ pad_an_int(N, P));``    ``}``}`

Output:

```Before Padding: 123