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Example of bash loops

Here are some examples of Bash loops:

**For Loop**

A For loop is used to iterate over a sequence (like an array) and execute a block of code

for each item in the sequence.

bash

fruits=(apple banana orange)
for fruit in "${fruits[@]}"; do
  echo "The current fruit is: $fruit"
done

Output:

The current fruit is: apple

The current fruit is: banana

The current fruit is: orange

**While Loop**

A While loop continues to execute a block of code as long as the condition specified in

its test expression is true.

bash

i=0
while [ $i -lt 5 ]; do
  echo "Iteration $i"
  ((i++))
done

Output:

Iteration 0

Iteration 1

Iteration 2

Iteration 3

Iteration 4

**Until Loop**

An Until loop is similar to a While loop, but it continues to execute a block of code as

long as the condition specified in its test expression is false.

bash

i=0
until [ $i -eq 5 ]; do
  echo "Iteration $i"
  ((i++))
done

Output:

Iteration 0

Iteration 1

Iteration 2

Iteration 3

Iteration 4

**For-Each Loop**

A For-each loop is used to iterate over an array and execute a block of code for each

item in the array.

bash

colors=(red green blue)
for color in "${colors[@]}"; do
  echo "The current color is: $color"
done

Output:

The current color is: red

The current color is: green

The current color is: blue

**For-In Loop**

A For-in loop is used to iterate over an associative array (or a hash table) and execute

a block of code for each key-value pair in the array.

bash

declare -A person=(["name"]="John" ["age"]="30")
for name in "${!person[@]}"; do
  echo "The current key is: $name"
  echo "The value for this key is: ${person[$name]}"
done

Output:

The current key is: name

The value for this key is: John

The current key is: age

The value for this key is: 30