String. Split full test

A field in the database is spliced with commas (,). Each field is the primary key of another table. You need to query the child element or delete the element for the field spliced with commas, there will be more complex string parsing.

Therefore, the split method provided by string is tested first.

As you can see, all the commas before the element are considered as delimiters and are split into a string array;

Then the comma is discarded.

Therefore, when parsing fields, we should focus on "Remove the comma before" to ensure that the prime value of the string array is the primary key of the table, rather than an empty string.

@Test    public void testSplit() {        String str1 = "1,2,3";        String[] strArr1 = str1.split(",");        String str2 = "1,2,";        String[] strArr2 = str2.split(",");        String str3 = ",2,3";        String[] strArr3 = str3.split(",");        String str4 = ",";        String[] strArr4 = str4.split(",");        String str5 = ",,";        String[] strArr5 = str5.split(",");        String str6 = ",,6";        String[] strArr6 = str6.split(",");        String str7 = "7,,";        String[] strArr7 = str7.split(",");        String str8 = ",8,";        String[] strArr8 = str8.split(",");        System.out.println("str1="+str1);        for (int i = 0; i <strArr1.length; i++) {            System.out.println("strArr1["+i+"]="+strArr1[i]);        }        System.out.println("**************************************");                System.out.println("str2="+str2);        for (int i = 0; i <strArr2.length; i++) {            System.out.println("strArr2["+i+"]="+strArr2[i]);        }        System.out.println("**************************************");        System.out.println("str3="+str3);        for (int i = 0; i <strArr3.length; i++) {            System.out.println("strArr3["+i+"]="+strArr3[i]);        }        System.out.println("**************************************");        System.out.println("str4="+str4);        for (int i = 0; i <strArr4.length; i++) {            System.out.println("strArr4["+i+"]="+strArr4[i]);        }        System.out.println("**************************************");        System.out.println("str5="+str5);        for (int i = 0; i <strArr5.length; i++) {            System.out.println("strArr5["+i+"]="+strArr5[i]);        }        System.out.println("**************************************");        System.out.println("str6="+str6);        for (int i = 0; i <strArr6.length; i++) {            System.out.println("strArr6["+i+"]="+strArr6[i]);        }        System.out.println("**************************************");        System.out.println("str7="+str7);        for (int i = 0; i <strArr7.length; i++) {            System.out.println("strArr7["+i+"]="+strArr7[i]);        }        System.out.println("**************************************");        System.out.println("str8="+str8);        for (int i = 0; i <strArr8.length; i++) {            System.out.println("strArr8["+i+"]="+strArr8[i]);        }        /**str1=1,2,3strArr1[0]=1strArr1[1]=2strArr1[2]=3**************************************str2=1,2,strArr2[0]=1strArr2[1]=2**************************************str3=,2,3strArr3[0]=strArr3[1]=2strArr3[2]=3**************************************str4=,**************************************str5=,,**************************************str6=,,6strArr6[0]=strArr6[1]=strArr6[2]=6**************************************str7=7,,strArr7[0]=7**************************************str8=,8,strArr8[0]=strArr8[1]=8*/            }

2. Add new elements to the old string

 

3. delete an element from the old string

String. Split full test