Step 1: Understand the Task

Before writing the function, we need to understand the concepts behind decimal and hexadecimal numbers. Decimals are base-10 system and can have values ranging from 0 to 9. In contrast, hexadecimals are base-16 and have values ranging from 0-9 and A-F, where A-F represent 10-15 respectively.

Step 2: Identify Inputs and Outputs

Next, we need to identify what our function will take as input and return as output. Here, we are converting a decimal number to hexadecimal, so our function will take in an integer as input and return a hexadecimal number in String format.

public String decimalToHexa(int num) {
}

Step 3: Create a Mapping of Decimal to Hexadecimal Characters

To convert a decimal number to hexadecimal, we need a way to map decimal numbers to their equivalent hexadecimal characters. This can be done by creating a character array as shown below.

public String decimalToHexa(int num) {
char[] hexaDecimals = {'0','1','2','3','4','5','6','7','8','9','A','B','C','D','E','F'};
}

Step 4: Implementing the Conversion Logic

The standard way to convert a decimal number to hexadecimal is to divide the decimal number by 16 (which is the base for hexadecimal) and then map the remainder to a hexadecimal character. We can implement this using a while loop.

public String decimalToHexa(int num) {
char[] hexaDecimals = {'0','1','2','3','4','5','6','7','8','9','A','B','C','D','E','F'};
String hexa = "";
while(num>0) {
int remainder = num % 16;
hexa = hexaDecimals[remainder] + hexa;
num /= 16;
}
return hexa;
}

Step 5: Conclusion:

Finally, we created a function that can convert decimal numbers to hexadecimal. The logic here is straightforward: we simply divided the input number by 16 and mapped the remainder to the hexadecimal character. This process was repeated until num was greater than 0.