JAVA --数字与字符串（二）字符串转换

系统管理员 2022-12-09 02:46 219阅读 0赞

## 数字转字符串 ##

方法1： 使用String类的静态方法valueOf  
方法2： 先把基本类型装箱为对象，然后调用对象的toString

**String.vlaueof(变量名)**

**Integer对象.toString()**

public class TestNumber {
        
    	public static String getType(Object o) {
        
    		return o.getClass().toString();
    	}
    	public static void main(String args[]) {
        
    		int i =5;
    		System.out.println(getType(i));
    		
    		
    		String a = String.valueOf(i);//方法一
    		System.out.println(getType(a));
    
    		Integer it = i;
    		String name = it.toString();//方法二
    		System.out.println(getType(name));
    	}
    }

## 字符串转数字 ##

**Integer.parseInt(变量名)方法**

public class TestNumber {
        
    	public static String getType(Object o) {
        
    		return o.getClass().toString();
    	}
    	public static void main(String args[]) {
        
    		String a = "500";
    		
    		int b = Integer.parseInt(a);
    		System.out.println(getType(b));
    		System.out.println(b);
    	}
    }

## 练习-字符串转换 ##

public class TestNumber {
        
    	public static String getType(Object o) {
        
    		return o.getClass().toString();
    	}
    	public static void main(String args[]) {
        
    		float a = 3.14f;
    		
    		String b = String.valueOf(a);
    		System.out.println(getType(b));
    		
    		float a1 = Float.valueOf(b);
    		System.out.println(getType(a1));
    	}
    }

万能转换：

int a = 1;
    String a1 = String.valueOf(a);
    
    String a = "100";
    int a1 = Integer.valueOf(a);
    
    float a = 3.14;
    String a1 = String.valueOf(a);
    
    String a = "3.14";
    float a1 = Float.valueOf(a);