java例程练习（计算子串个数）

public class Test {
public static void main(String[] args) {
String s = "sunjavahahajavaokjavamyjavagoodjava";
String sToFind = "java";

int count = 0;
int index = s.indexOf(sToFind);

if(index != -1) {
count ++;
}

s = s.substring(index + sToFind.length());
while(s.indexOf(sToFind) != -1) {
index = s.indexOf(sToFind);
s = s.substring(index + sToFind.length());
count++;
}

System.out.println(count);

}
}

//优化后

public class Test {
public static void main(String[] args) {
String s = "sunjavahahajavaokjavamyjavagoodjava";
String sToFind = "java";

int count = 0;
int index = -1;

while((index = s.indexOf(sToFind)) != -1) {
s = s.substring(index + sToFind.length());
count++;
}

System.out.println(count);
}
}