(Java, JavaScript, Python) Comparison of string processing

Java, JavaScript, Python processing comparison

I recently started studying JavaScript and Python. As a summary of what I learned, I would like to write an article comparing the processing of Java, JavaScript, and Python. This time it is character string processing.

Comparison list of character string processing

Postscript

--Match comparison --Java equalsIgnoreCase () performs case-insensitive match comparisons. -=== The operator makes a strict comparison including the type. '123'=== 123 → false --Search --Returns the character index of the match: indexOf (), lastIndexOf (), find (), rfind () --Returns true/false: contains (), includes (), in expression, not in expression --Match judgment of first character, return true/false: startsWith () --Match judgment of last character, return true/false: endsWith () --Blank removal --In both languages, single-byte spaces, tabs, and line breaks are removed. --In addition to the above, Java strip () also removes double-byte spaces. --The Python function can specify the character to be deleted as an argument. If omitted, spaces, tabs, and line breaks will be deleted. --Category conversion --Python has more detailed conversion functions than the other two. capitalize () → convert first letter to uppercase and others to lowercase, title () → word first letter to uppercase and others to lowercase, swapcase () → swap case --Cut out --substring () can omit the end index, in which case the end of the string is the end index. --JavaScript cutout substring () and slice () are the same in normal usage, but the result will be different if the arguments are irregular. --If start index> end index, substring () will automatically replace the start and end, and slice () will return an empty string. --If a negative number is specified, substring () treats the argument as 0, and slice () treats it as "string length-argument". --Python uses slices of the form "string [start: end]" instead of functions. Either start or end can be omitted. If ":" is omitted, one character is acquired like charAt (). --Replace --Java: replace () replaces all matched characters, replaceFirst () replaces the first matched character. --JavaScript: replace () replaces the first matched character, replaceAll () replaces all matched characters, but replace () can also replace all characters with the regular expression option "g". --Python: replace () can specify the maximum number of substitutions in the third argument like split (). --Python: translate () can replace multiple cases. However, the replacement source character must be one character. Specify the replacement combination with "str.maketrans ()". "" AbCdefghIk ".translate (str.maketrans ({'C':'c','I':'ij'}))" --Regular expressions can be used in each language as follows. - Java：replaceFirst()、replaceAll()
- JavaScript：replace()、replaceAll()
--Python: re.sub (), re.subn (), subn returns a replaced string + a list of converted numbers (to be exact, tuples). --Split by delimiter --Split () can specify the maximum number of splits in the second argument in any language. --Regular expressions can be used for split () in Java and JavaScript. In JavaScript, the space delimiter is specified as "/ \ s /" with a regular expression. --For Python, the re module re.split () can use regular expressions. --The argument of split () in Python can be omitted. If omitted, spaces, tabs, and line breaks will be split. --Python's rsplit () is different from split () in counting from the right when the maximum number of divisions is specified in the second argument. --Python splitlines () splits with line breaks. It also supports OS-dependent line breaks. --Arbitrary molding --Python has several formats. See the sample below for format (). --One is% operator: sei ='Yamada' mei ='Taro', print ('name:% s% s'% (sei, mei)) --One is f string: print (f'name: {sei} {mei}')

sample

Java

public class StringSample {

    public static void main(String[] args) {
        StringSample obj = new StringSample();
        obj.executeSample();
    }

    public void executeSample() {
        String str = "Yamada,Taro,Yamada,Taro,M,19950827,25 years old,2 Kanda Sakumacho, Chiyoda-ku, Tokyo-XX-XX〇〇so";

        //White space removal
        String strKuhaku1 = str.trim();

        //Divide by delimiter
        String[] strBun1 = strKuhaku1.split(",");

        //Simple join
        String resName = new StringBuilder().append(strBun1[0]).append(strBun1[1]).toString();

        //Case conversion
        String strOoko1 = strBun1[2].toUpperCase();
        String strOoko2 = strBun1[3].toUpperCase();

        //Simple join
        String resAlpha = strOoko1.concat(" ").concat(strOoko2);

        //Match comparison
        String resSex;
        if (strBun1[4].equals("M")) {
            resSex = "male";
        } else {
            resSex = "Female";
        }

        //Cut out
        String strKiri1 = strBun1[5].substring(0, 4);
        String strKiri2 = strBun1[5].substring(4, 6);
        String strKiri3 = strBun1[5].substring(6);

        //Combine by delimiter
        String resBirth = String.join("/", strKiri1, strKiri2, strKiri3);

        //Replacement
        String resAge = strBun1[6].replace("Talent", "age");

        //String length
        String resAddress = strBun1[7];
        if (16 < strBun1[7].length()) {
            resAddress = strBun1[7].substring(0, 16);
            //Simple join
            resAddress = resAddress + "(Abbreviation)";
        }

        //Search
        String resMessage1 = "";
        String resMessage2 = "";
        if (strBun1[7].startsWith("Tokyo")) {
            resMessage1 = "It is the capital.";
        }
        if (strBun1[7].contains("Chiyoda Ward")) {
            resMessage2 = "There is Tokyo station.";
        }

        //Arbitrary molding
        String res1 = String.format("%s(%s)Mr%s %s raw(%s)", resName, resAlpha, resSex, resBirth, resAge);
        String res2 = String.format("%s %s%s", resAddress, resMessage1, resMessage2);

        //repetition
        String line = "-".repeat(64);

        System.out.println(line);
        System.out.println(res1);
        System.out.println(res2);
        System.out.println(line);
    }
}

JavaScript

<html>
<head>
<script>
function executeSample() {
        let str = "Yamada,Taro,Yamada,Taro,M,19950827,25 years old,2 Kanda Sakumacho, Chiyoda-ku, Tokyo-XX-XX〇〇so";

        //White space removal
        let strKuhaku1 = str.trim();

        //Divide by delimiter
        let strBun1 = strKuhaku1.split(",");

        //Simple join
        let resName = strBun1[0] + strBun1[1];

        //Case conversion
        let strOoko1 = strBun1[2].toUpperCase();
        let strOoko2 = strBun1[3].toUpperCase();

        //Simple join
        let resAlpha = strOoko1.concat(" ", strOoko2);

        //Match comparison
        let resSex;
        if (strBun1[4] == "M") {
            resSex = "male";
        } else {
            resSex = "Female";
        }

        //Cut out
        let strKiri1 = strBun1[5].substring(0, 4);
        let strKiri2 = strBun1[5].substring(4, 6);
        let strKiri3 = strBun1[5].substring(6);

        //Combine by delimiter
        let resBirth = [strKiri1, strKiri2, strKiri3].join("/");

        //Replacement
        let resAge = strBun1[6].replace("Talent", "age");

        //String length
        let resAddress = strBun1[7];
        if (16 < strBun1[7].length) {
            resAddress = strBun1[7].substring(0, 16);
            //Simple join
            resAddress = resAddress + "(Abbreviation)";
        }

        //Search
        let resMessage1 = "";
        let resMessage2 = "";
        if (strBun1[7].startsWith("Tokyo")) {
            resMessage1 = "It is the capital.";
        }
        if (strBun1[7].includes("Chiyoda Ward")) {
            resMessage2 = "There is Tokyo station.";
        }

        //Arbitrary molding
        let res1 = `${resName}(${resAlpha})Mr${resSex} ${resBirth}Living(${resAge})`;
        let res2 = `${resAddress} ${resMessage1}${resMessage2}`;

        //repetition
        let line = "-".repeat(64);

        console.log(line);
        console.log(res1);
        console.log(res2);
        console.log(line);
    }
</script>
</head>
<body onload="executeSample()">
  <h1>Qiita article</h1>
  <h2>String processing</h2>
</body>
</html>

Python

str1 = "Yamada,Taro,Yamada,Taro,M,19950827,25 years old,2 Kanda Sakumacho, Chiyoda-ku, Tokyo-XX-XX〇〇so"

#White space removal
strKuhaku1 = str1.strip()

#Divide by delimiter
strBun1 = strKuhaku1.split(",")

#Simple join
resName = strBun1[0] + strBun1[1]

#Case conversion
strOoko1 = strBun1[2].upper()
strOoko2 = strBun1[3].upper()

#Simple join
resAlpha = strOoko1 + " " + strOoko2

#Match comparison
resSex = ""
if strBun1[4] == "M":
    resSex = "male"
else:
    resSex = "Female"

#Cut out
strKiri1 = strBun1[5][0:4]
strKiri2 = strBun1[5][4:6]
strKiri3 = strBun1[5][6:]

#Combine by delimiter
resBirth = "/".join([strKiri1, strKiri2, strKiri3])

#Replacement
resAge = strBun1[6].replace("Talent", "age")

#String length
resAddress = strBun1[7]
if 16 < len(strBun1[7]):
    resAddress = strBun1[7][:16]
    #Simple join+
    resAddress = resAddress + "(Abbreviation)"

#Search
resMessage1 = ""
resMessage2 = ""
if strBun1[7].startswith("Tokyo"):
    resMessage1 = "It is the capital."
if  "Chiyoda Ward" in strBun1[7]:
    resMessage2 = "There is Tokyo station."

#Arbitrary molding
res1 = "{}({})Mr{} {}Living({})".format(resName, resAlpha, resSex, resBirth, resAge)
res2 = "{} {}{}".format(resAddress, resMessage1, resMessage2)

#repetition*
line = "-" * 64

print(line)
print(res1)
print(res2)
print(line)

Output result

----------------------------------------------------------------
Taro Yamada(YAMADA TARO)Mr. Male 1995/08/27 students(25 years old)
2 Kanda Sakumacho, Chiyoda-ku, Tokyo-X(Abbreviation)It is the capital. There is Tokyo station.
----------------------------------------------------------------