获取子字符串索引位置--indexOf方法与lastIndexOf方法

た入场券 2024-02-18 18:16 108阅读 0赞

package com;
    
    public class GetStringIndex {
    
    	public static void main(String[] args) {
    		String str ="明月几时有，把酒问青天";
    		System.out.println(str);
    		int charIndex =str.indexOf("酒");
    		System.out.println("字符‘酒’首次出现的索引为："+charIndex);
    
    	}
    
    }

![20180221114139222][]

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package com;
    
    public class GetStringIndex {
    
    	public static void main(String[] args) {
    		String str ="we are the world";
    		System.out.println(str);
    		int charIndex =str.indexOf("e");
    		System.out.println("字符‘e’首次出现的索引为："+charIndex);
    		int charIndex2 =str.indexOf("e",4);
    		System.out.println("字符‘e’在索引4之后第一次出现的位置："+charIndex2);
    
    		System.out.println();
    		String str2 = "let it go!let it go!";
    		System.out.println(str2);
    		int index = str2.lastIndexOf("t");
    		System.out.println("字符t最后一次出现的位置:"+index);
    		int index2 =str2.lastIndexOf("t",14);
    		System.out.println("从索引14的位置往前查第一个t出现的位置:"+index2);
    		
    
    	}
    
    }

![20180224144455452][]

[20180221114139222]: https://image.dandelioncloud.cn/pgy_files/images/2024/01/29/001a0f6caa984979a6ce028a4448236a.png
[20180224144455452]: https://image.dandelioncloud.cn/pgy_files/images/2024/01/29/6aabbc1efd0e4fc0893581e65e5b983b.png