Double loop statement (triangle diamond exercise)

99 multiplication table

while statement:

#!/bin/bash
# 99乘法表
a=1
while [ $a -le 9 ]
  do
  b=1       
    while [ $b -le $a ]
        do  
           c=$[$a*$b]
           echo  -ne "$a*$b=$c\t"      
    let b++  
         done 
    let a++   
    echo ""
   done
    
~          

rectangle

#!/bin/bash

for ((i=1;i<=10;i++  ))
   do
   
    for (( j=1;j<=20;j++))
       do   
         echo -n "*"
       done 
    echo ""
    done   

Right triangle

#!/bin/bash
for ((a=1;a<=9;a++))
do
  for ((b=1;b<=$a;b++))
  do
  echo -n "*"

  done
 echo ""
done
~                                                                                                 
~      

Anti-right triangle

#!/bin/bash
for ((a=1;a<=9;a++))
do
  for ((b=9;b>=$a;b--))
  do
  echo -n " "
  done
 for ((c=1;c<=$a;c++))
 do
 echo -n "*"

 done
echo ""
done
~        

Inverted right triangle

#!/bin/bash
for ((a=1;a<=9;a++))
do
  for ((b=9;b>=$a;b--))
  do
  echo -n "*"
  done
 echo ""
done
~     

Isosceles triangle

#!/bin/bash
for ((a=1;a<=9;a++))
do
   for ((b=9;b>=$a;b--))
   do
   echo -n " "
   done

  for ((c=1;c<=$[$a*2-1];c++))
  do
  echo -n "*" 
  done
 echo ""
done

Inverted isosceles triangle

#!/bin/bash

for (( i=1; i<=10; i++ ))
do
     for (( j=1; j<=$i; j++ ))
     do
     echo -n " "
     done 
     for(( k=10; k>=$i; k-- ))
     do     
     echo -n "*"
     done   
     for (( l=9;l>=$i;l--))
     do 
     echo -n "*"
     done 
echo " "
done
~     

Isosceles trapezoid

#!/bin/bash
for ((a=1;a<=9;a++))
do
    for ((b=9;b>=$a;b--))
    do
    echo -n " "
    done
   for ((c=1;c<=9;c++))
   do
   echo -n "*"
   done
  for ((d=1;d<=$[$a*2-1];d++))
  do
  echo -n "*"
  done
 echo ""    
done    

diamond

#!/bin/bash
for ((i=1;i<=11;i++ ))
    do
        for ((j=10;j>=$i;j-- ))
        do
        echo  -n  "  "
        done
        for (( k=1;k<=$i;k++ ))
       do
       echo -n "*"
       done
       for (( l=2;l<=$i;l++ ))
       do
       echo -n "*"
       done
 echo " "
 done
 
 for ((i=1;i<=10;i++ ))
  do
    for((j=1;j<=$i;j++ ))
    do
    echo -n " "
    done
    for  (( k=10;k>=$i;k-- ))
     do
     echo -n "*"
     done
    for (( l=9;l>=$i;l-- ))
     do
     echo -n "*"
     done
  echo " "
  done

Adjustable diamond

#!/bin/bash
#
read -p " 请输入大小  " d
for ((i=1;i<=$d;i++ ))
    do
    for ((j=$d-1;j>=$i;j-- ))
     do
      echo -n " "
     done
     for (( k=1;k<=$i;k++ ))
     do
     echo -n "*"
     done
     for (( l=2;l<=$i;l++ ))
     do
     echo -n "*"
     done
echo " "
done


for ((i=1;i<=$d-1;i++ ))
  do
    for((j=1;j<=$i;j++ ))
    do
    echo -n " "
    done
    for  (( k=$d-1;k>=$i;k-- ))
     do
     echo -n "*"
     done
    for (( l=$d-2;l>=$i;l-- ))
     do
     echo -n "*"
     done
  echo " "
  done

Parallelogram

for (( i=1; i<=5; i++ ))
do
     for (( j=1; j<=$i; j++ ))
     do
     echo -n " "
     done 
     for (( k=1; k<=5; k++ )) 
            
     do     
     echo -n "**" 
     done  
echo " "
done          
~