Strings AOK

.data
S1: .asciiz "I "
S2: .asciiz "love "
S3: .asciiz "assembly"
string1: .asciiz "The first string is: "
string2: .asciiz "\nThe second string is: "
string3: .asciiz "\nThe third string is: "
string4: .space 16
S4: .asciiz "\nThe three strings combined are: "

.text
main:
    #display all three strings first
    li $v0, 4
    la $a0, string1
    syscall
    la $a0, S1
    syscall
    la $a0, string2
    syscall
    la $a0, S2
    syscall
    la $a0, string3
    syscall
    la $a0, S3
    syscall

    #concat
    la $a0, string4
    la $a1, S1
    la $a2, S2
    la $a3, S3
    jal strcatFirst

    #print
    jal printConcat

    #exit
    li $v0, 10
    syscall

strcatFirst:
        lb $t0, ($a1)
        beqz $t0, strcatSecond
        sb $t0, ($a0)
        addi $a1, $a1, 1
        addi $a0, $a0, 1
    j strcatFirst

    strcatSecond:
        lb $t0,($a2)
        beqz $t0, strcatThird
        sb $t0, ($a0)
        addi $a2, $a2, 1
        addi $a0, $a0, 1
        j strcatSecond

    strcatThird:
        lb $t0, ($a3)
        beqz $t0, endStrcat
        sb $t0, ($a0)
        addi $a3, $a3, 1
        addi $a0, $a0, 1
        j strcatThird

    endStrcat:
        jr $ra

printConcat:

    #print label
    li $v0, 4
    la $a0, S4
    syscall

    #print string4
    li $v0, 4
    la $a0, string4
    syscall

    jr $ra