# The repeat loop in R

To execute a block of code more than once in a continuous loop, the repeat keyword or loop is utilised in R. However, the repeat statement presents no condition to exit from the loop, and this is where the need for the break statement arises.

Process flow for Repeat loop:

Step 1: Initialization of variables.

Step 2: Execution of the block of statements inside the repeat loop.

Step 3: Use an expression inside the repeat loop to exit the loop.

Step 4: Check for the exit condition.

Step 5: Execution of the break statement to exit from the loop for the true condition.

Step 6: Repeat the execution of the block of statements inside the repeat loop for the false condition.

### Syntax:

```repeat { commands if(condition) { break } }```

### Example 1:

```var <- 2 repeat { print(var) var = var+2 if (var == 10){ break } }```

Output:

```[1] 2   [1] 4   [1] 6   [1] 8```

### Example 2:

```var <- 1 repeat { print("Process in Progress"); if(var >= 5) break var<-var+1 }```

Output:

```[1] "Process in Progress"   [1] "Process in Progress"   [1] "Process in Progress"   [1] "Process in Progress"   [1] "Process in Progress"```

### Example 3:

```msg <- c("I","am","working","on","it.") count <- 1 repeat { print(msg) count <- count + 1 if(count > 5) { break } }```

Output:

```[1] "I" "am" "working" "on" "it."   [1] "I" "am" "working" "on" "it."   [1] "I" "am" "working" "on" "it."   [1] "I" "am" "working" "on" "it."   [1] "I" "am" "working" "on" "it."```

### Example 4:

```sum <- 0 { num <-100 num <-as.integer(num) } repeat{ sum <- sum + num num = num+1 if(num>105){ break } } cat("100+101+102+103+104+105 =",sum)```

Output:

`100+101+102+103+104+105 = 615`

### Example 5:

```sum <- 0 num <-5 repeat{ sum = sum + num num = num + 1 cat("\nSUM =",sum) if(num>20){ break } }```

Output:

```SUM = 5   SUM = 11   SUM = 18   SUM = 26   SUM = 35   SUM = 45   SUM = 56   SUM = 68   SUM = 81   SUM = 95   SUM = 110   SUM = 126   SUM = 143   SUM = 161   SUM = 180   SUM = 200```

### Example 6:

```var <- 2 repeat { if(var == 20) break if(var == 10){ var = var+2 next } print(var) var <- var+2 }```

Output:

```[1] 2   [1] 4   [1] 6   [1] 8   [1] 12   [1] 14   [1] 16   [1] 18```

### Example 7: Square of a Number:

```iteration_count <- 10 iteration_count <- as.integer(iteration_count) num <-1 repeat{ cat("\nSquare of",num,"=",(num*num)) if(num == iteration_count) break num <- num+1 }```

Output:

```Square of 1 = 1   Square of 2 = 4   Square of 3 = 9   Square of 4 = 16   Square of 5 = 25   Square of 6 = 36   Square of 7 = 49   Square of 8 = 64   Square of 9 = 81   Square of 10 = 100```

### Example 8: Cube of a Number:

```iteration_count <- 10 iteration_count <- as.integer(iteration_count) num <-1 repeat{ cat("\nCube of",num,"=",(num*num*num)) if(num == iteration_count) break num <- num+1 }```

Output:

```Cube of 1 = 1   Cube of 2 = 8   Cube of 3 = 27   Cube of 4 = 64   Cube of 5 = 125   Cube of 6 = 216   Cube of 7 = 343   Cube of 8 = 512   Cube of 9 = 729   Cube of 10 = 1000```

### Example 9: Multiplication Table:

```iteration_count <- 10 iteration_count <- as.integer(iteration_count) num <-5 factor <-1 cat("Multiplication Table of 5\n") repeat{ cat("\n",num,"*",factor,"=",(num*factor)) if(factor == iteration_count) break factor <- factor+1 }```

Output:

```Multiplication Table of 5   5 * 1 = 5   5 * 2 = 10   5 * 3 = 15   5 * 4 = 20   5 * 5 = 25   5 * 6 = 30   5 * 7 = 35   5 * 8 = 40   5 * 9 = 45   5 * 10 = 50   &nbsp;```