Ytdyklly

Does apex include any programming idioms to quickly and clearly initialise or pad strings with a specific character, for example 'string multiplication' such as '-'*40 to easily create a rule, or '.'*(size-str.length() to pad to length?

I new to apex, though experienced developer; I want to produce a quick and simple bar graph of a specific dataset to highlight any anomalies. This code will render a bar-graph to the logs, seems very 'old school', surely there is better way to do this in apex? I want something that is clear and concise. Surely there is a way to do without the nested loop in the produce bar graph part of the code?

// retrieve distribution data

Integer distribution = new Integer[100];

for(Integer i=0; i<1000 ; i++) {

    // the real data actual comes from elsewhere;

    // this just simulates it with random numbers for this example.

    Integer num = (math.random() * 100).intValue();

    System.assert(num >= 0 && num < 100, 'Value out of expected range : ' + num);

    if (distribution[num] == null) {

        distribution[num] = 1;

    } else {

        distribution[num]++;

    }

}



// produce bar graph

String barGraph = 'n';

for(Integer num=0; num<100 ; num++) {

    barGraph += '' + num + ') ';

    // Surely there is better way to do this bit?

    for(integer i=0 ; i<distribution[num] ; i++) { barGraph += '.'; }

    barGraph += 'n';

}

System.Debug( barGraph );

Using the comment by @kurunve for direction, and for the benefit of others, this is the improved code using rightPad.

// single line rule.

System.Debug( ''.rightPad(40, '-' ));

// produce bar graph

String barGraph = 'n';

for(Integer num=0; num<100 ; num++) {

    barGraph += '' + num + ') '.rightPad(distribution[num], '+') + 'n';

}

System.Debug( barGraph );

// produce double line rule.

System.Debug( ''.rightPad(40, '=' ));

You can use String.Repeat

String.repeat Returns the current String repeated the specified number
of times.

String s1 = 'SFDC';

String s2 = 

   s1.repeat(2);

System.assertEquals(

   'SFDCSFDC', s2);

Also if you want a delimiter in between you can also specify that.

String s1 = 'SFDC';

String s2 = 

   s1.repeat('-', 2);

System.assertEquals(

   'SFDC-SFDC', s2);

Src : https://developer.salesforce.com/docs/atlas.en-us.apexcode.meta/apexcode/apex_methods_system_string.htm#apex_System_String_repeat