Arrays and Iterations

Arrays are declared in PL/I using the declare statement as for simple variables. No special keyword is needed; the array and its dimensions and subscript ranges are declared by including a bound specification after the identifier. In the declaration <math display='block'> <mrow> <mi>D</mi><mi>E</mi><mi>C</mi><mi>L</mi><mi>A</mi><mi>R</mi><mi>E</mi><mtext>&#x2009;</mtext><mi>A</mi><mn>1</mn><mrow><mo>(</mo> <mrow> <mn>0</mn><mo>:</mo><mn>3</mn> </mrow> <mo>)</mo></mrow><mo>;</mo> </mrow> </math>]]</EquationSource><EquationSource Format="TEX"><![CDATA[$$DECLARE\;A1\left( {0:3} \right);$$ a one-dimensional array of four elements A1(0), A1(1), A1(2) and A1(3) is declared. Every array element has the same attributes of mode, base, scale and precision — in this case the default attributes. In the declaration\ <math display='block'> <mrow> <mi>D</mi><mi>E</mi><mi>C</mi><mi>L</mi><mi>A</mi><mi>R</mi><mi>E</mi><mtext>&#x2009;</mtext><mi>A</mi><mn>2</mn><mrow><mo>(</mo> <mrow> <mo>&#x2212;</mo><mn>2</mn><mo>:</mo><mo>+</mo><mn>2</mn><mo>,</mo><mn>0</mn><mo>:</mo><mn>5</mn> </mrow> <mo>)</mo></mrow><mtext>&#x2009;</mtext><mi>F</mi><mi>I</mi><mi>X</mi><mi>E</mi><mi>D</mi><mtext>&#x2009;</mtext><mi>D</mi><mi>E</mi><mi>C</mi><mi>I</mi><mi>M</mi><mi>A</mi><mi>L</mi><mo>;</mo> </mrow> </math>]]</EquationSource><EquationSource Format="TEX"><![CDATA[$$DECLARE\;A2\left( { - 2: + 2,0:5} \right)\;FIXED\;DECIMAL;$$ a two-dimensional array of 5 * 6 = 30 elements is declared, each element being a fixed-point decimal number of default precision. When the lower bound of a subscript range is 1, as in <math display='block'> <mrow> <mi>D</mi><mi>E</mi><mi>C</mi><mi>L</mi><mi>A</mi><mi>R</mi><mi>E</mi><mtext>&#x2009;</mtext><mrow><mo>(</mo> <mrow> <mi>B</mi><mn>1</mn><mrow><mo>(</mo> <mrow> <mn>1</mn><mo>:</mo><mn>10</mn> </mrow> <mo>)</mo></mrow><mo>,</mo><mi>B</mi><mn>2</mn><mrow><mo>(</mo> <mrow> <mn>1</mn><mo>:</mo><mn>6</mn><mo>,</mo><mn>1</mn><mo>:</mo><mn>9</mn> </mrow> <mo>)</mo></mrow> </mrow> <mo>)</mo></mrow><mtext>&#x2009;</mtext><mi>F</mi><mi>L</mi><mi>O</mi><mi>A</mi><mi>T</mi><mrow><mo>(</mo> <mn>7</mn> <mo>)</mo></mrow><mo>;</mo> </mrow> </math>]]</EquationSource><EquationSource Format="TEX"><![CDATA[$$DECLARE\;\left( {B1\left( {1:10} \right),B2\left( {1:6,1:9} \right)} \right)\;FLOAT\left( 7 \right);$$ which is a factored declaration, the lower bound may be omitted, with its colon, it being taken as 1 by default <math display='block'> <mrow> <mi>D</mi><mi>E</mi><mi>C</mi><mi>L</mi><mi>A</mi><mi>R</mi><mi>E</mi><mtext>&#x2009;</mtext><mrow><mo>(</mo> <mrow> <mi>B</mi><mn>1</mn><mrow><mo>(</mo> <mrow> <mn>10</mn> </mrow> <mo>)</mo></mrow><mo>,</mo><mi>B</mi><mn>2</mn><mrow><mo>(</mo> <mrow> <mn>6</mn><mo>,</mo><mn>9</mn> </mrow> <mo>)</mo></mrow> </mrow> <mo>)</mo></mrow><mtext>&#x2009;</mtext><mi>F</mi><mi>L</mi><mi>O</mi><mi>A</mi><mi>T</mi><mrow><mo>(</mo> <mn>7</mn> <mo>)</mo></mrow><mo>;</mo> </mrow> </math>]]</EquationSource><EquationSource Format="TEX"><![CDATA[$$DECLARE\;\left( {B1\left( {10} \right),B2\left( {6,9} \right)} \right)\;FLOAT\left( 7 \right);$$