How to truncate in java

In simplest terms, truncation means to chop off the decimal portion of a number.

A method of approximating a decimal number by dropping all decimal places past a certain point without rounding.

Given a double value and a decimal place truncate the value to the given decimal point.

Example: 

Input: val = 3.142857142857143 Decimal point = 3 Output = 3.142 Upto 3 decimal places

 Approach 1: Using Mathematically :

• Shift the decimal of the given value to the given decimal point by multiplying 10^n
• Take the floor of the number and divide the number by 10^n
• The final value is the truncated value

Approach 2: Using String matching approach

• Convert the number into String
• Start the counter variable when “.” found in the String
• Increment the counter till decimal point
• Store the new String and parse it in double format