String 转换为 int

String str = "123";
int n = Integer.valueOf(str);

int n2 = Integer.parseInt(str);

String 转换为 int数组

String str = "1234";
int[] arr = new int[str.length()];
for(int i=0;i<str.length();i++){
	arr[i] = Integer.parseInt(str.substring(i,i+1));
}

String 转换为 String数组

String str = "123";
String[] sarr = str.split("");

String 转换为 char数组

String str = "123";
char[] arr = str.toCharArray();

String数组转换为 String

String[] str = {"12", "av"};
StringBuffer sb = new StringBuffer();
for (int i=0; i<str.length;i++){
	sb.append(str[i]);
}
String s = sb.toString();

int 转换为 String

int n = 123;
String s = String.valueOf(n);

int n = 123;
String s = n + "";

Integer n = 123;
String s = Integer.toString(n);

int数组转换为 String数组

int[] arr = {1,2,3};
StringBuilder sb = new StringBuilder();
for (int j : arr) {
	sb.append(j);
}
String s = sb.toString();
String[] sarr = s.split("");

int数组转换为 int

int[] arr = {1,2,3,4};
int number = 0;
for (int i : arr){
	number = number * 10 + i;
}

int 转换为 int数组

int number = 1234;
String str = String.valueOf(number);
int[] arr = new int[str.length()];
for (int i=0;i<str.length();i++){
	arr[i] = Integer.parseInt(str.substring(i,i+1));
}