Related Articles

# Java lang.Long.numberOfTrailingZeros() method in Java with Examples

• Last Updated : 23 May, 2019

java.lang.Long.numberOfTrailingZeros() is a built-in function in Java which returns the number of trailing zero bits to the right of the lowest order set bit. In simple terms, it returns the (position-1) where position refers to the first set bit from the right. If the number does not contain any set bit(in other words, if the number is zero), it returns 64.

Syntax:

```public static long numberOfTrailingZeros(long num)
Parameters:
num - the number passed
Returns:
the number of trailing zeros after the lowest-order set bit
```

Examples:

```Input :  8
Output : 3
Explanation: Binary representation of 8 is 1000
No of trailing zeros to the right of the lowest-order set
bit is 3.

Input : 191
Output : 0
```

The program below illustrates the java.lang.Long.numberOfTrailingZeros() function:

Program 1:

 `// Java program that demonstrates the``// Long.numberOfTrailingZeros() function`` ` `// include lang package``import` `java.lang.*;`` ` `public` `class` `GFG {`` ` `    ``public` `static` `void` `main(String[] args)``    ``{`` ` `        ``long` `l = ``8``;`` ` `        ``// returns the number of zero bits following the lowest-order``        ``// set bit``        ``System.out.println(``"Number of trailing zeros = "``                           ``+ Long.numberOfTrailingZeros(l));`` ` `        ``// second example``        ``l = ``25``;``        ``System.out.println(``"Number of trailing zeros = "``                           ``+ Long.numberOfTrailingZeros(l));``    ``}``}`

Output:

```Number of trailing zeros = 3
Number of trailing zeros = 0
```

Program 2: The program below demonstrates the use of function when a negative number is passed.

 `// Java program that demonstrates the``// Long.numberOfTrailingZeros() function``// negative number``// include lang package``import` `java.lang.*;`` ` `public` `class` `GFG {`` ` `    ``public` `static` `void` `main(String[] args)``    ``{`` ` `        ``long` `l = -``12``;`` ` `        ``// returns the number of zero bits following the lowest-order``        ``// set bit``        ``System.out.println(``"Number of trailing zeros = "``                           ``+ Long.numberOfTrailingZeros(l));``    ``}``}`

Output:

```Number of trailing zeros = 2
```

It returns an error message when a decimal a string value is passed as an argument.
Program 3: When a decimal value is passed in argument.

 `// Java program that demonstrates the``// Long.numberOfTrailingZeros() function``// decimal value as an argument`` ` `// include lang package``import` `java.lang.*;`` ` `public` `class` `GFG {`` ` `    ``public` `static` `void` `main(String[] args)``    ``{`` ` `        ``// returns the number of zero bits following the lowest-order``        ``// set bit``        ``System.out.println(``"Number of trailing zeros = "``                           ``+ Long.numberOfTrailingZeros(``12.34``));``    ``}``}`

Output:

```prog.java:16: error: incompatible types: possible lossy conversion from double to long
System.out.println("Number of trailing zeros = "+Long.numberOfTrailingZeros(12.34));
```

Program 4: When a string value is passed in argument.

 `// java program that demonstrates the``// Long.numberOfTrailingZeros() function``// string value as an argument`` ` `// include lang package``import` `java.lang.*;`` ` `public` `class` `GFG {`` ` `    ``public` `static` `void` `main(String[] args)``    ``{`` ` `        ``// returns the number of zero bits following the lowest-order``        ``// set bit``        ``System.out.println(``"Number of trailing zeros = "``                           ``+ Long.numberOfTrailingZeros(``"100"``));``    ``}``}`

Output:

```prog.java:15: error: incompatible types: String cannot be converted to long
System.out.println("Number of trailing zeros = "+Long.numberOfTrailingZeros("100"));
```

Attention reader! Don’t stop learning now. Get hold of all the important Java Foundation and Collections concepts with the Fundamentals of Java and Java Collections Course at a student-friendly price and become industry ready. To complete your preparation from learning a language to DS Algo and many more,  please refer Complete Interview Preparation Course.

My Personal Notes arrow_drop_up