String 方法 閱讀英文 儲存 共用方式為 Facebookx.comLinkedIn電子郵件 String.IndexOf Method Reference Feedback Definition Namespace: Java.Lang Assembly: Mono.Android.dll Overloads 展開資料表 IndexOf(Int32) Returns the index within this string of the first occurrence of the specified character. ...
The first example demonstrates a simple Java String IndexOf method that takes only one character type parameter: String str =newString ("Udemy Java Tutorials");intindexOfJ = str.indexOf('J');intindexOfj = str.indexOf('j');intindexOfq = str.indexOf('q');System.out.println(indexOfJ)...
StringmyStr="Hello planet earth, you are a great planet.";System.out.println(myStr.indexOf("planet")); Try it Yourself » Definition and Usage TheindexOf()method returns the position of the first occurrence of specified character(s) in a string. ...
str.indexOf(String substr); 用来查询str中字符substr的位置,起始位置为0,若str中不存在substr,则返回-1 。 例: publicclassTest1 { publicstaticvoidmain(String[] args) { //TODO Auto-generated method stub String str = "1234567890"; intindex = str.indexOf("1"); System.out.println(index); } ...
publicclassStringPerformanceTest{publicstaticvoidmain(String[]args){Stringstr="Hello, World!";longstartTime=System.currentTimeMillis();for(inti=0;i<10000;i++){str.substring(1,5);}longendTime=System.currentTimeMillis();System.out.println("Substring method time: "+(endTime-startTime)+" ms")...
Java String lastIndexOf Method: The lastIndexOf() method returns the index within this string of the last occurrence of the specified character.
1.indexOf方法的基本语法 indexOf方法的基本语法如下: intindexOf(intch)intindexOf(intch,intfromIndex)intindexOf(Stringstr)intindexOf(Stringstr,intfromIndex) 1. 2. 3. 4. ch:要搜索的字符值或字符 str:要搜索的字符串 fromIndex:开始搜索的索引位置(可选参数,默认为0) ...
Java String indexOf() The indexOf() method returns the index of the first occurrence of the specified character/substring within the string. Example class Main { public static void main(String[] args) { String str1 = "Java is fun"; int result; // getting index of character 's' resul...
s.indexOf("a", 1) 这行的意思是 从字符串s里寻找字母a的位置，但寻找的时候要从s的索引为1的位置开始，这就是第二个参数1的作用，由于索引是从0开始的，这样实际寻找的时候是从字母b开始的，这样肯定就找不到a了，所以输出了-1，-1的意思就是没有找到。说的有点啰嗦 你...
System.out.println(result);// 7// substring not in the stringresult = str1.lastIndexOf("java"); System.out.println(result);// -1} } Run Code Note:The character'a'occurs multiple times in the"Learn Java"string. ThelastIndexOf()method returns the index of the last occurrence of'a'...