String与整数和数组之间的转换

Posted 2020-10-12 闫真真

//声明字符串s1，整数a，数组aa,并赋初始值
String s1 = "123";
int a = 22;
int[] aa = new int[] {1,2,3,4};

//将字符串转换为整数
int a1 = Integer.parseInt(s1);
System.out.println("转换后a1 = "+a1);

Integer a2 = Integer.valueOf(s1);
System.out.println("转换后a2 = "+a2);

int a3 = Integer.valueOf(s1);
System.out.println("转换后a3 = "+a3);

System.out.println("************ ");

//整数转换为字符串
String s2 = String.valueOf(a);
System.out.println("转换后s2 = "+s2);

System.out.println("************ ");

//将字符串转换为数组
char[] aa1 = s1.toCharArray();

System.out.println("for循环----- ");
System.out.print("转换后aa1的值： ");
for(int i=0;i<aa1.length;i++) {
System.out.print(aa1[i]);
}
System.out.println("\n"+"增强for循环----- ");
System.out.print("转换后aa1的值： ");
for(char i:aa1) {
System.out.print(i);
}

System.out.println("\n"+"************ ");
//将数组转换成字符串
StringBuffer sb = new StringBuffer();
for(int i = 0; i < aa.length; i++){
sb. append(aa[i]);
}
String s4 = sb.toString();
System.out.println("转换后s4 = "+s4);