老是记不住字符串和数字相互转化的方法,这次统一记录一下。
String转成不同类型的数字都有对应的XXX.valueOf(str)方法;
类似的不同类型的数字转成String也有XXX.toString(num)方法。
package test;
public class StringAndNumConvertToEachOther {
public static void main(String[] args) {
String str = "0131829.23";
String str2 = "232";
int num = 23424;
float fnum = 2.3424F;
Double dnum = 2.342;
// String to num
System.out.println("String to num");
System.out.println("方法一:");
System.out.println("字符串转整型" + Integer.parseInt(str2)); // 方法一
System.out.println("字符串转浮点型" + Float.parseFloat(str));
System.out.println("字符串转Double" + Double.parseDouble(str));
System.out.println("方法二:");
System.out.println("字符串转整型" + Integer.valueOf(str2)); // 方法二
System.out.println("字符串转浮点型" + Float.valueOf(str));
System.out.println("字符串转Double" + Double.valueOf(str));
// num to string
System.out.println("num to string");
System.out.println("方法一:");
System.out.println("整型转字符串" + num + ""); // 方法一
System.out.println("浮点型转字符串" + fnum + "");
System.out.println("Double转字符串" + dnum + "");
System.out.println("方法二:");
System.out.println("任意数字转字符串" + String.valueOf(num)); // 方法二
System.out.println("任意数字转字符串" + String.valueOf(fnum));
System.out.println("任意数字转字符串" + String.valueOf(dnum));
System.out.println("方法三:");
System.out.println("整型数字转字符串" + Integer.toString(num)); // 方法三
System.out.println("浮点型数字转字符串" + Float.toString(fnum));
System.out.println("Double数字转字符串" + Double.toString(dnum));
}
}