4. Process control
4.1. Branch structure
1.if statement
void main() {
int score = 80;
if (score >= 90) {
print('优秀');
} else if (score >= 80) {
print('良好');
} else if (score >= 70) {
print('中等');
} else if (score >= 60) {
print('及格');
} else {
print('不及格');
};
}
2.switch statement
void main() {
int level = 20;
switch (level) {
case 1:
print('初级会员');
break;
case 2:
print('中级会员');
break;
case 3:
print('高级会员');
break;
default:
print('普通用户');
}
}
4.2. Loop structure
1.for circulation
void main() {
var list = [1, 2, 3, 4, 5];
for (var i = 0; i < list.length; i++) {
print(i);
}
}
2.for ... in circulation
void main() {
var list = [1, 2, 3, 4, 5];
for (var item in list) {
print(item);
}
}
3.while cycle
void main() {
int i = 0;
while (i < 10) {
i++;
print(i);
}
}
4.do ... while loop
void main() {
int i = 0;
do {
i++;
print(i);
} while (i < 10);
}
5.break和continue
void main() {
for ( var i = 0; i < 100; i++) {
if (i % 2 == 1) {
break; // 直接退出循环
}
print(i);
}
}
void main() {
for ( var i = 0; i < 100; i++) {
if (i % 2 == 1) {
continue; // 退出本次循环,继续下次循环
}
print(i);
}
}
Screw classroom video lessons Address: http://edu.nodeing.com