TextView textView = findViewById(R.id.text);
EditText editText = findViewById(R.id.edit);
Button button = findViewById(R.id.button);
button.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
int num = Integer.parseInt(editText.getText().toString());
int sum = 0;
for(int i = 0; i <= num; i+=2) {
sum += i;
}
textView.setText(sum + "");
}
});
if(i=0;i<=输入的数字,i++){
if(i%2==0){
sum+=i
}
}
你在for循环里面最后再加一个i++不就步进是2了?
int sum = 0;
for (int i = 0; i <= n; i+=2) {
sum += i;
}