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我无法理解，为什么编译器只显示正在运行（永远），当我在此程序中将char更改为int时。通过改变我的意思是使用只是整数采取选项号码，因此在开关中使用int数字本身。查询char/int的相关输入
这是一个正常的字符1这是working-
public static void main(String args[])
throws java.io.IOException{
char option; int i=0;
do{
if(i==1)
System.out.println("\nNotice: Wrong option chosen, pick again.");
i=1;
System.out.println("Help on:");
System.out.println("1. if");
System.out.println("2. switch");
System.out.println("3. while");
System.out.println("4. do-while");
System.out.println("5. for");
System.out.println("Pick any option for brief informatrion.");
option= (char)System.in.read();
}while(option<'1' || option>'5');
switch(option){
case '1':
System.out.println("The If:\n");
System.out.println("If(condition) statement;");
System.out.println("else statement;");
break;
case '2':
System.out.println("The Switch:\n");
System.out.println("switch(expression){");
System.out.println(" case constant:");
System.out.println(" statement sequence");
System.out.println(" break;");
System.out.println(" // ...");
System.out.println("}");
break;
case '3':
System.out.println("The While:\n");
System.out.println("while(condition statement;)");
break;
case '4':
System.out.println("The Do-While:\n");
System.out.println("do{");
System.out.println(" statement;");
System.out.println("}while(condition);");
break;
case '5':
System.out.println("The For:\n");
System.out.println("for(init; condition; iteration){");
System.out.println(" statement;");
System.out.println("}");
break;
}
}
}
这是INT 1，它只是不断运行forver
public static void main(String args[])
throws java.io.IOException{
int option; int i=0;
do{
if(i==1)
System.out.println("\nNotice: Wrong option chosen, pick again.");
i=1;
System.out.println("Help on:");
System.out.println("1. if");
System.out.println("2. switch");
System.out.println("3. while");
System.out.println("4. do-while");
System.out.println("5. for");
System.out.println("Pick any option for brief informatrion.");
option= System.in.read();
}while(option<1 || option>5);
switch(option){
case 1:
System.out.println("The If:\n");
System.out.println("If(condition) statement;");
System.out.println("else statement;");
break;
case 2:
System.out.println("The Switch:\n");
System.out.println("switch(expression){");
System.out.println(" case constant:");
System.out.println(" statement sequence");
System.out.println(" break;");
System.out.println(" // ...");
System.out.println("}");
break;
case 3:
System.out.println("The While:\n");
System.out.println("while(condition statement;)");
break;
case 4:
System.out.println("The Do-While:\n");
System.out.println("do{");
System.out.println(" statement;");
System.out.println("}while(condition);");
break;
case 5:
System.out.println("The For:\n");
System.out.println("for(init; condition; iteration){");
System.out.println(" statement;");
System.out.println("}");
break;
}
}
}