Java String toLowerCase() 与示例

Java String toLowerCase()方法用于字符串，我们希望将字符串中的所有字母转换为小写。

toLowerCase()方法有两种类型，如下所示：

1. toLowerCase()
2. toLowerCase(Locale loc)：使用给定 Locale 的规则将所有字符转换为小写。

Note: Internally toLowerCase() works in similar way as toLowerCase(Locale.getDefault()) method.  

句法：

public String toLowerCase()

public String toLowerCase(Locale loc) 

该方法的封装视图如下：

--> java.util Package
    --> String Class
        --> toLowerCase() Method  

参数：要应用的区域设置值

返回类型：以小写字母返回字符串

示例 1：

java

// Java Program to Demonstrate Working of
// toLowerCase() Method of String Class
  
// Importing required classes
import java.util.*;
  
// Main class
class GFG {
  
    // Main driver method
    public static void main(String args[])
    {
  
        // Custom input string
        String s = "Geeks for Geeks";
  
        // Converting string s to lowercase letter
        String s2 = s.toLowerCase();
  
        // Printing the lowercase string corresponding
        // to input string
        System.out.println(s2);
    }
}

输出

geeks for geeks

示例 2：

Java

// Java program to demonstrate Working of toLowerCase()
// Method present inside Locale class
  
// Importing required classes
import java.util.Locale;
  
// Main class
class GFG {
  
    // Main driver method
    public static void main(String args[])
    {
        // Custom input string
        String s = "I Know YOI Bui You Don't Know ME";
  
        // Locales with the language "tr" for TURKISH
        //"en" for ENGLISH is created
        Locale TURKISH = Locale.forLanguageTag("tr");
        Locale ENGLISH = Locale.forLanguageTag("en");
  
        // Converting string s to lowercase letter
        // using TURKISH and ENGLISH language
        String gfg2 = s.toLowerCase(TURKISH);
        String gfg3 = s.toLowerCase(ENGLISH);
  
        // Printing above string
        System.out.println(gfg2);
        System.out.println(gfg3);
    }
}

输出

? know yo? bui you don't know me
i know yoi bui you don't know me