Java – StringBuilder insert() method

May 25, 2017 SJ String Handling 0

In this article, we will discuss StringBuilder’s insert() method which is used to insert specified argument at the specified offset (or say starting from specified index-position)

1. StringBuilder’s insert() method:

  • This method is used to insert passed-argument to the buffer at the specified offset (or starting from specified index-position)
  • before inserting, internally converts respective data-type into String format first
  • Note: There are 12 variants or overloaded insert() method, those are,

1.1 Method Signature:

public StringBuilder insert(int offset, boolean b);

public StringBuilder insert(int offset, char c);

public StringBuilder insert(int offset, char[] str);

public StringBuilder insert(int index, char[] str, int offset, int len);

public StringBuilder insert(int dstOffset, CharSequence s);

public StringBuilder insert(int dstOffset, CharSequence s, int start, int end);

public StringBuilder insert(int offset, double d);

public StringBuilder insert(int offset, float f);

public StringBuilder insert(int offset, int i);

public StringBuilder insert(int offset, long l);

public StringBuilder insert(int offset, Object obj);

public StringBuilder insert(int offset, String str);

1.2 Returns:

  • Returns StringBuilder object after inserting given argument at the specified offset
  • Argument can be any primitive data-types like boolean, char, int, long, float, double, etc.
  • It can also be used to insert char[] array, CharSequence, Object or String

2. Examples on insert() method :

  1. To insert specified primitive boolean data-type
  2. To insert specified primitive int data-type
  3. To insert specified primitive long data-type
  4. To insert specified primitive float data-type
  5. To insert specified primitive double data-type
  6. To insert specified primitive char data-type
  7. To insert specified char[] array date-type
  8. To insert specified CharSequence data-type
  9. To insert specified String object

2.1 To insert specified primitive boolean data-type :

  • Insert boolean-value into StringBuilder object at specified offset or index-position

Method signature:

public StringBuilder insert(int offset, boolean b);

StringBuilderInsertMethodForBoolean.java

package in.bench.resources.stringbuilder.methods;

public class StringBuilderInsertMethodForBoolean {

	public static void main(String[] args) {

		// define boolean variable
		boolean boolTest1 = true;
		boolean boolTest2 = false;

		// StringBuilder - 1
		StringBuilder sb1 = new StringBuilder(
				"The boolean value  is inserted");

		// 1. A : before inserting -
		// internally invokes toString() method
		System.out.println("1.A Before inserting  : " + sb1);

		// insert at 18th index insert(offset, boolean) method
		sb1.insert(18, boolTest1);

		// 1. B : after inserting -
		// internally invokes toString() method
		System.out.println("1.B After inserting"
				+ " at 18th postion : " + sb1);

		// StringBuilder - 2
		StringBuilder sb2 = new StringBuilder(
				" boolean value is inserted at 0th index");

		// 2. A : before inserting -
		// internally invokes toString() method
		System.out.println("\n\n2.A Before inserting  : " + sb2);

		// insert at 0th index insert(offset, boolean) method
		sb2.insert(0, boolTest2);

		// 2. B : after inserting -
		// internally invokes toString() method
		System.out.println("2.B After inserting"
				+ " at 0th postion : " + sb2);
	}
}

Output:

1.A Before inserting  :
	The boolean value  is inserted
1.B After inserting at 18th postion :
	The boolean value true is inserted

2.A Before inserting  :
	boolean value is inserted at 0th index
2.B After inserting at 0th postion :
	false boolean value is inserted at 0th index

2.2 To insert specified primitive int data-type :

  • Insert integer-value into StringBuilder object at specified offset or index-position

Method signature:

public StringBuilder insert(int offset, int i);

StringBuilderInsertMethodForInteger.java

package in.bench.resources.stringbuilder.methods;

public class StringBuilderInsertMethodForInteger {

	public static void main(String[] args) {

		// define int variable
		int iTest1 = 19;
		int iTest2 = 333;

		// StringBuilder - 1
		StringBuilder sb1 = new StringBuilder(
				"BenchResources.Net");

		// 1. A : before inserting -
		// internally invokes toString() method
		System.out.println("1.A Before inserting  : " + sb1);

		// insert at 5th index using insert(offset, int) method
		sb1.insert(5, iTest1);

		// 1. B : after inserting -
		// internally invokes toString() method
		System.out.println("1.B After inserting"
				+ " at 5th postion : " + sb1);

		// StringBuilder - 2
		StringBuilder sb2 = new StringBuilder(
				" BenchResources.Net");

		// 2. A : before inserting -
		// internally invokes toString() method
		System.out.println("\n\n2.A Before inserting  : " + sb2);

		// insert at 15th index using insert(offset, int) method
		sb2.insert(15, iTest2);

		// 2. B : after inserting -
		// internally invokes toString() method
		System.out.println("2.B After inserting"
				+ " at 15th postion : " + sb2);
	}
}

Output:

1.A Before inserting  : BenchResources.Net
1.B After inserting at 5th postion : Bench19Resources.Net

2.A Before inserting  :  BenchResources.Net
2.B After inserting at 15th postion :  BenchResources333.Net

2.3 To insert specified primitive long data-type :

  • Insert long-value into StringBuilder object at specified offset or index-position

Method signature:

public StringBuilder insert(int offset, long l);

StringBuilderInsertMethodForLong.java

package in.bench.resources.stringbuilder.methods;

public class StringBuilderInsertMethodForLong {

	public static void main(String[] args) {

		// define long variable
		long lngTest1 = 1912345;
		long lngTest2 = 333444999;

		// StringBuilder - 1
		StringBuilder sb1 = new StringBuilder("Google.com");

		// 1. A : before inserting -
		// internally invokes toString() method
		System.out.println("1.A Before inserting  : " + sb1);

		// insert at 6th index using insert(offset, long) method
		sb1.insert(6, lngTest1);

		// 1. B : after inserting -
		// internally invokes toString() method
		System.out.println("1.B After inserting"
				+ " at 6th postion : " + sb1);

		// StringBuilder - 2
		StringBuilder sb2 = new StringBuilder("Oracle.com");

		// 2. A : before inserting -
		// internally invokes toString() method
		System.out.println("\n\n2.A Before inserting  : " + sb2);

		// insert at 0th index using insert(offset, long) method
		sb2.insert(0, lngTest2);

		// 2. B : after inserting -
		// internally invokes toString() method
		System.out.println("2.B After inserting"
				+ " at 15th postion : " + sb2);
	}
}

Output:

1.A Before inserting  : Google.com
1.B After inserting at 6th postion : Google1912345.com

2.A Before inserting  : Oracle.com
2.B After inserting at 15th postion : 333444999Oracle.com

2.4 To insert specified primitive float data-type :

  • Insert float-value into StringBuilder object at specified offset or index-position

Method signature:

public StringBuilder insert(int offset, float f);

StringBuilderInsertMethodForFloat.java

package in.bench.resources.stringbuilder.methods;

public class StringBuilderInsertMethodForFloat {

	public static void main(String[] args) {

		// define float variable
		float ftTest1 = 19.23456f;
		float ftTest2 = 258.589635f;

		// StringBuilder - 1
		StringBuilder sb1 = new StringBuilder(
				"Hello it's float value of ");

		// 1. A : before inserting -
		// internally invokes toString() method
		System.out.println("1.A Before inserting  : " + sb1);

		// insert at 26th index using insert(offset, float) method
		sb1.insert(sb1.length(), ftTest1);

		// 1. B : after inserting -
		// internally invokes toString() method
		System.out.println("1.B After inserting"
				+ " at 26th postion : " + sb1);

		// StringBuilder - 2
		StringBuilder sb2 = new StringBuilder(
				" is a float another value");

		// 2. A : before inserting -
		// internally invokes toString() method
		System.out.println("\n\n2.A Before inserting  : " + sb2);

		// insert at 0th index using insert(offset, float) method
		sb2.insert(0, ftTest2);

		// 2. B : after inserting -
		// internally invokes toString() method
		System.out.println("2.B After inserting"
				+ " at 0th postion : " + sb2);
	}
}

Output:

1.A Before inserting  :
	Hello it's float value of
1.B After inserting at 26th postion :
	Hello it's float value of 19.23456

2.A Before inserting  :
	is a float another value
2.B After inserting at 0th postion :
	258.58963 is a float another value

2.5 To insert specified primitive double data-type :

  • Insert double-value into StringBuilder object at specified offset or index-position

Method signature:

public StringBuilder insert(int offset, double d);

StringBuilderInsertMethodForDouble.java

package in.bench.resources.stringbuilder.methods;

public class StringBuilderInsertMethodForDouble {

	public static void main(String[] args) {

		// define double variable
		double dblTest1 = 19.23456;
		double dblTest2 = 258.589635;

		// StringBuilder - 1
		StringBuilder sb1 = new StringBuilder(
				"Hello it's double value of ");

		// 1. A : before inserting -
		// internally invokes toString() method
		System.out.println("1.A Before inserting  : " + sb1);

		// insert at 26th index using insert(offset,double) method
		sb1.insert(sb1.length(), dblTest1);

		// 1. B : after inserting -
		// internally invokes toString() method
		System.out.println("1.B After inserting"
				+ " at 26th postion : " + sb1);

		// StringBuilder - 2
		StringBuilder sb2 = new StringBuilder(
				" is double another value.");

		// 2. A : before inserting -
		// internally invokes toString() method
		System.out.println("\n\n2.A Before inserting  : " + sb2);

		// insert at 0th index using insert(offset, double) method
		sb2.insert(0, dblTest2);

		// 2. B : after inserting -
		// internally invokes toString() method
		System.out.println("2.B After inserting"
				+ " at 0th postion : " + sb2);
	}
}

Output:

1.A Before inserting  :
	Hello it's double value of
1.B After inserting at 26th postion :
	Hello it's double value of 19.23456

2.A Before inserting  :
	is double another value.
2.B After inserting at 0th postion :
	258.589635 is double another value.

2.6 To insert specified primitive char data-type :

  • Insert character-value into StringBuilder object at specified offset or index-position

Method signature:

public StringBuilder insert(int offset, char c);

StringBuilderInsertMethodForChar.java

package in.bench.resources.stringbuilder.methods;

public class StringBuilderInsertMethodForChar {

	public static void main(String[] args) {

		// define char variable
		char chTest1 = 'A';
		char chTest2 = 'b';

		// StringBuilder - 1
		StringBuilder sb1 = new StringBuilder(
				"The upper-case character is ");

		// 1. A : before inserting -
		// internally invokes toString() method
		System.out.println("1.A Before inserting  : " + sb1);

		// insert at 25th index insert(offset, char) method
		sb1.insert(28, chTest1);

		// 1. B : after inserting -
		// internally invokes toString() method
		System.out.println("1.B After inserting"
				+ " at 25th postion : " + sb1);

		// StringBuilder - 2
		StringBuilder sb2 = new StringBuilder(
				" is a lower-case character.");

		// 2. A : before inserting -
		// internally invokes toString() method
		System.out.println("\n\n2.A Before inserting  : " + sb2);

		// insert at 0th index insert(offset, char) method
		sb2.insert(0, chTest2);

		// 2. B : after inserting -
		// internally invokes toString() method
		System.out.println("2.B After inserting"
				+ " at 0th postion : " + sb2);
	}
}

Output:

1.A Before inserting  :
	The upper-case character is
1.B After inserting at 25th postion :
	The upper-case character is A

2.A Before inserting  :
	is a lower-case character.
2.B After inserting at 0th postion :
	b is a lower-case character.

2.7 To insert specified char[] array :

  • Insert char[] array into StringBuilder object at specified offset or index-position

Method signature:

public StringBuilder insert(int offset, char[] str);

public StringBuilder insert(int index, char[] str, int offset, int len);

StringBuilderInsertMethodForCharArray.java

package in.bench.resources.stringbuilder.methods;

public class StringBuilderInsertMethodForCharArray {

	public static void main(String[] args) {

		// define char[] variable
		char[] chArrayTest1 = {'Y', 'a', 'h', 'o', 'o'};
		char[] chArrayTest2 = {'h', 'o', 't',
				'm', 'a', 'i', 'l', '.', 'c', 'o', 'm'};

		// StringBuilder - 1
		StringBuilder sb1 = new StringBuilder(
				"Implicitly converted char[] to SB ");

		// 1. A : before inserting -
		// internally invokes toString() method
		System.out.println("1.A Before inserting  : " + sb1);

		// insert at 34th index insert(offset, char[]) method
		sb1.insert(sb1.length(), chArrayTest1);

		// 1. B : after inserting -
		// internally invokes toString() method
		System.out.println("1.B After inserting"
				+ " at 34th postion : " + sb1);

		// StringBuilder - 2
		StringBuilder sb2 = new StringBuilder(
				" is a convreted SB from char[] array.");

		// 2. A : before inserting -
		// internally invokes toString() method
		System.out.println("\n\n2.A Before inserting  : " + sb2);

		// insert at 0th index insert(offset, char[]) method
		sb2.insert(0, chArrayTest2);

		// 2. B : after inserting -
		// internally invokes toString() method
		System.out.println("2.B After inserting"
				+ " at 0th postion : " + sb2);
	}
}

Output:

1.A Before inserting  :
	Implicitly converted char[] to SB
1.B After inserting at 34th postion :
	Implicitly converted char[] to SB Yahoo

2.A Before inserting  :
	is a convreted SB from char[] array.
2.B After inserting at 0th postion :
	hotmail.com is a convreted SB from char[] array.

2.8 To insert specified CharSequence :

  • Insert CharSequence-value into StringBuilder object at specified offset or index-position

Method signature:

public StringBuilder insert(int dstOffset, CharSequence s);

public StringBuilder insert(int dstOffset, CharSequence s, int start, int end);

StringBuilderInsertMethodForCharSequence.java

package in.bench.resources.stringbuilder.methods;

public class StringBuilderInsertMethodForCharSequence {

	public static void main(String[] args) {

		// define CharSequence variable
		CharSequence charSeq1 = "Make";
		CharSequence charSeq2 = "Travels.enjoy";

		// StringBuilder - 1
		StringBuilder sb1 = new StringBuilder("MyTrip.com");

		// 1. A : before inserting -
		// internally invokes toString() method
		System.out.println("1.A Before inserting  : " + sb1);

		// insert at 0th index insert(offset, CharSequence) method
		sb1.insert(0, charSeq1);

		// 1. B : after inserting -
		// internally invokes toString() method
		System.out.println("1.B After inserting"
				+ " at 0th postion : " + sb1);

		// StringBuilder - 2
		StringBuilder sb2 = new StringBuilder("HoneyMoon");

		// 2. A : before inserting -
		// internally invokes toString() method
		System.out.println("\n\n2.A Before inserting  : " + sb2);

		// insert at 5th index insert(offset, CharSequence) method
		sb2.insert(sb2.length(), charSeq2);

		// 2. B : after inserting -
		// internally invokes toString() method
		System.out.println("2.B After inserting"
				+ " at 5th postion : " + sb2);
	}
}

Output:

1.A Before inserting  : MyTrip.com
1.B After inserting at 0th postion : MakeMyTrip.com

2.A Before inserting  : HoneyMoon
2.B After inserting at 5th postion : HoneyMoonTravels.enjoy

2.9 To insert specified String object :

  • Insert String object/value into StringBuilder object at specified offset or index-position

Method signature:

public StringBuilder insert(int offset, Object obj);

public StringBuilder insert(int offset, String str);

StringBuilderInsertMethodForStringObject.java

package in.bench.resources.stringbuilder.methods;

public class StringBuilderInsertMethodForStringObject {

	public static void main(String[] args) {

		// define String variable
		String str1 = "Bench";
		String str2 = "Tutorial.tut";

		// StringBuilder - 1
		StringBuilder sb1 = new StringBuilder("Resources.Net");

		// 1. A : before inserting -
		// internally invokes toString() method
		System.out.println("1.A Before inserting  : " + sb1);

		// insert at 0th index insert(offset, String) method
		sb1.insert(0, str1);

		// 1. B : after inserting -
		// internally invokes toString() method
		System.out.println("1.B After inserting"
				+ " at 0th postion : " + sb1);

		// StringBuilder - 2
		StringBuilder sb2 = new StringBuilder("Online");

		// 2. A : before inserting -
		// internally invokes toString() method
		System.out.println("\n\n2.A Before inserting  : " + sb2);

		// insert at 6th index insert(offset, String) method
		sb2.insert(sb2.length(), str2);

		// 2. B : after inserting -
		// internally invokes toString() method
		System.out.println("2.B After inserting"
				+ " at 6th postion : " + sb2);
	}
}

Output:

1.A Before inserting  : Resources.Net
1.B After inserting at 0th postion : BenchResources.Net

2.A Before inserting  : Online
2.B After inserting at 6th postion : OnlineTutorial.tut

Related Articles:

References:

Happy Coding !!
Happy Learning !!

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Java - StringBuilder indexOf() method

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