java是什么 java如何判断字符串中某个位置的值。用substring能解决吗/?

java如何判断字符串中某个位置的值。用substring能解决吗/?String s1=“10010001”String s2=“10020030001”//提取第四个字符串sub1=s1.subs

java如何判断字符串中某个位置的值。用substring能解决吗/?

String s1=“10010001”String s2=“10020030001”//提取第四个字符串sub1=s1.substring(3,%4)String sub2=s1.substring(3,%4)或char c1=s1.charAt(3)char c2=s2.charAt(3)