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Java String trim()

De Java String class trim() metoden eliminerar ledande och efterföljande utrymmen. Unicode-värdet för blanksteg är 'u0020'. Trim()-metoden i Java-strängen kontrollerar detta Unicode-värde före och efter strängen, om den finns tar metoden bort mellanslagen och returnerar den utelämnade strängen.

Strängtrim()-metoden utelämnar inte mellanslag.

Signatur

Signaturen eller syntaxen för metoden String class trim() ges nedan:

 public String trim()

Returnerar

sträng med utelämnade ledande och efterföljande mellanslag

Internt genomförande

 public String trim() { int len = value.length; int st = 0; char[] val = value; /* avoid getfield opcode */ while ((st <len) && (val[st] <=" " )) { st++; } while ((st len) (val[len - 1] 0) || (len value.length)) ? substring(st, : this; pre> <h2>Java String trim() Method Example</h2> <p> <strong>FileName:</strong> StringTrimExample.java</p> <pre> public class StringTrimExample{ public static void main(String args[]){ String s1=&apos; hello string &apos;; System.out.println(s1+&apos;javatpoint&apos;);//without trim() System.out.println(s1.trim()+&apos;javatpoint&apos;);//with trim() }} </pre> <span> Test it Now </span> <p> <strong>Output</strong> </p> <pre> hello string javatpoint hello stringjavatpoint </pre> <h2>Java String trim() Method Example 2</h2> <p>The example demonstrates the use of the trim() method. This method removes all the trailing spaces so the length of the string also reduces. Let&apos;s see an example.</p> <p> <strong>FileName:</strong> StringTrimExample2.java</p> <pre> public class StringTrimExample2 { public static void main(String[] args) { String s1 =&apos; hello java string &apos;; System.out.println(s1.length()); System.out.println(s1); //Without trim() String tr = s1.trim(); System.out.println(tr.length()); System.out.println(tr); //With trim() } } </pre> <p> <strong>Output</strong> </p> <pre> 22 hello java string 17 hello java string </pre> <h2>Java String trim() Method Example 3</h2> <p>The trim() can be used to check whether the string only contains white spaces or not. The following example shows the same.</p> <p> <strong>FileName:</strong> TrimExample3.java</p> <pre> public class TrimExample3 { // main method public static void main(String argvs[]) { String str = &apos; abc &apos;; if((str.trim()).length() &gt; 0) { System.out.println(&apos;The string contains characters other than white spaces 
&apos;); } else { System.out.println(&apos;The string contains only white spaces 
&apos;); } str = &apos; &apos;; if((str.trim()).length() &gt; 0) { System.out.println(&apos;The string contains characters other than white spaces 
&apos;); } else { System.out.println(&apos;The string contains only white spaces 
&apos;); } } } </pre> <p> <strong>Output</strong> </p> <pre> The string contains characters other than white spaces The string contains only white spaces </pre> <h2>Java String trim() Method Example 4</h2> <p>Since strings in Java are immutable; therefore, when the trim() method manipulates the string by trimming the whitespaces, it returns a new string. If the manipulation is not done by the trim() method, then the reference of the same string is returned. Observe the following example.</p> <p> <strong>FileName:</strong> TrimExample4.java</p> <pre> public class TrimExample4 { // main method public static void main(String argvs[]) { // the string contains white spaces // therefore, trimming the spaces leads to the // generation of new string String str = &apos; abc &apos;; // str1 stores a new string String str1 = str.trim(); // the hashcode of str and str1 is different System.out.println(str.hashCode()); System.out.println(str1.hashCode() + &apos;
&apos;); // no white space present in the string s // therefore, the reference of the s is returned // when the trim() method is invoked String s = &apos;xyz&apos;; String s1 = s.trim(); // the hashcode of s and s1 is the same System.out.println(s.hashCode()); System.out.println(s1.hashCode()); } } </pre> <p> <strong>Output</strong> </p> <pre> The string contains characters other than white spaces The string contains only white spaces </pre> <hr></len)>
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Produktion 

 hello string javatpoint hello stringjavatpoint

Java String trim() Metodexempel 2

Exemplet visar användningen av metoden trim(). Denna metod tar bort alla efterföljande utrymmen så att längden på strängen också minskar. Låt oss se ett exempel.

Filnamn: StringTrimExample2.java

 public class StringTrimExample2 { public static void main(String[] args) { String s1 =&apos; hello java string &apos;; System.out.println(s1.length()); System.out.println(s1); //Without trim() String tr = s1.trim(); System.out.println(tr.length()); System.out.println(tr); //With trim() } }

Produktion 

 22 hello java string 17 hello java string

Java String trim() Metodexempel 3

Trim() kan användas för att kontrollera om strängen bara innehåller blanksteg eller inte. Följande exempel visar detsamma.

Filnamn: TrimExample3.java

 public class TrimExample3 { // main method public static void main(String argvs[]) { String str = &apos; abc &apos;; if((str.trim()).length() &gt; 0) { System.out.println(&apos;The string contains characters other than white spaces 
&apos;); } else { System.out.println(&apos;The string contains only white spaces 
&apos;); } str = &apos; &apos;; if((str.trim()).length() &gt; 0) { System.out.println(&apos;The string contains characters other than white spaces 
&apos;); } else { System.out.println(&apos;The string contains only white spaces 
&apos;); } } }

Produktion 

 The string contains characters other than white spaces The string contains only white spaces

Java String trim() Metodexempel 4

Eftersom strängar i Java är oföränderliga; därför, när trim()-metoden manipulerar strängen genom att trimma blanktecken, returnerar den en ny sträng. Om manipulationen inte görs med metoden trim() returneras referensen för samma sträng. Observera följande exempel.

Filnamn: TrimExample4.java

 public class TrimExample4 { // main method public static void main(String argvs[]) { // the string contains white spaces // therefore, trimming the spaces leads to the // generation of new string String str = &apos; abc &apos;; // str1 stores a new string String str1 = str.trim(); // the hashcode of str and str1 is different System.out.println(str.hashCode()); System.out.println(str1.hashCode() + &apos;
&apos;); // no white space present in the string s // therefore, the reference of the s is returned // when the trim() method is invoked String s = &apos;xyz&apos;; String s1 = s.trim(); // the hashcode of s and s1 is the same System.out.println(s.hashCode()); System.out.println(s1.hashCode()); } }

Produktion 

 The string contains characters other than white spaces The string contains only white spaces