I tried to summarize the basics of kotlin and java

Introduction ...

This article was written in Previous article,

** 2nd day of article posting every day for 7 days **

It has become

The code to use is pasted below, but see the previous article for more details on the features of this app!

--java version: https://github.com/sato-na/guruwake_java

--kotlin version: https://github.com/sato-na/guruwake_kotlin

↓ This is the main subject of this article ↓

Comparing the basics of each language ...

-- table of contents --

1. How to define variables

2. How to write an if statement

3. How to write a for statement

4. How to change from String to Int

Variable definition method

--For java

Type variable name=initial value;

Type must be specified

Example)

ResultActivty.java

String rTxt = "";                //31st line
int memberNum = memberL.size();  //Line 33

--For kotlin

val/var variable name=initial value

It is necessary to specify val (immutable) or var (variable)

Example)

ResultActivity.kt

var rTxt = ""                 //Line 22
val memberNum = memberL.size  //24th line

How to write an if statement

--For java

if (conditions) {
    //Processing when the condition is true
}

Example)

ResultActivity.java

if (n <= memberNum % groupNumI) {  //39th line
    p++;
}

--For kotlin

if (conditions) {
    //Processing when the condition is true
}

Example)

ResultActivity.kt

if (n <= memberNum % groupNumI) {  //30th line
    p++
}

Same way of writing

How to write a for statement

--For java

for (Variables used when turning the for statement;Variable condition;Processing of variables after processing) {
    //Processing when entering a for statement
}

Example)

ResultActivity.java

for (int q = 0; q < p; q++) {              //Line 43
    rTxt += "  " + memberL.get(0) + "\n";
    memberL.remove(0);
}

--For kotlin

for (Variable used in for In Initial value of variable..Final value){
     //Processing when entering a for statement
}

Example)

ResultActivity.kt

for (q in 0..p-1) {                    //Line 34
    rTxt += "   " + memberL[0] + "\n"
    memberL.remove(memberL[0])
}

The method of specifying the number of for statements is different

How to change from String to Int

--For java

int variable= Integer.parseInt(String to change)

Example)

ResultActivity.java

final String groupNum = intent.getStringExtra("GROUP_NUM");  //26th line
int groupNumI = Integer.parseInt(groupNum);                  //32nd line

--For kotlin

val/var variable name: Int =Value to change.toInt()

Example)

ResultActivity.kt

val groupNum = intent.getStringExtra("GROUP_NUM")  //18th line
val groupNumI : Int = groupNum.toInt()             //Line 23

The syntax is very different

Finally…

This time I tried to summarize the basics of java and kotlin. I'm only using what's in the code on github, so Variable names are difficult to understand, and there are many functions not mentioned in this article. Maybe it was hard to understand ... However, I hope it's a little easier to understand than just the code.

I will post an article like this tomorrow, so please keep an eye on me.