字符串startsWith()方法 (String startsWith() Method)

startsWith() method is a String class method, it is used to check whether a given string starts with specific character sequences or not.

startsWith()方法是一个String类方法，用于检查给定的字符串是否以特定的字符序列开头。

If a string starts with given character sequences – startsWith() method returns true, if a string does not start with the given character sequences – startsWith() method returns false.

如果字符串以给定的字符序列开头-startsWith()方法将返回true ，如果字符串不是以给定的字符序列开头-则startsWith()方法将返回false 。

Syntax:

句法：

    boolean String_object.startsWith(character_sequence);

Here,

这里，

• String_object is the main string in which we have to check whether it starts with given character_sequence or not.

  String_object是主要字符串，我们必须在其中检查是否以给定的character_sequence开头。

• character_sequence is the set of character to be checked.

  character_sequence是要检查的字符集。

Example:

例：

    Input:
str = "Hello world!"
Function call:
str.startsWith("Hello");
Output:
true
Input:
str = "IncludeHelp"
Function call:
str.startsWith("inc");
Output:
false

Code:

码：

public class Main
{
public static void main(String[] args) {
String str1 = "Hello world!";
String str2 = "IncludeHelp";
System.out.println(str1.startsWith("Hello"));
System.out.println(str1.startsWith("inc"));
//checking through the conditions
if(str1.startsWith("Hello")){
System.out.println(str1 + " starts with Hello" );
}
else{
System.out.println(str1 + " does not start with Hello" );
}
//note: method is case sensitive
if(str2.startsWith("inc")){
System.out.println(str2 + " starts with inc" );
}
else{
System.out.println(str2 + " does not start with inc" );
}        
}
}

Output

输出量

true
false
Hello world! starts with Hello
IncludeHelp does not start with inc

翻译自: https://www.includehelp.com/java/string-startsWith-method-with-example.aspx